I came across Decode string problem which is given an encoded string s, decode it With rule:
N[encoded] => encoded*N.
Examples:
$input = "4[abc]";
// output: abcabcabcabc
$input = "ac3[ab]d";
// output: acabababd
$input = "a2[b3[cd]]";
// output: abcdcdcdbcdcdcd
I have tried solving it, using string manipulation with if conditions, It works only for two inputs, However it fails at last one when the given input has multiple encoded string.
$output = '';
$arr = str_split($input);
for ($i=0; $i < count($arr); $i++) {
$char = $arr[$i];//current character
if($char == '['){
$closed = strpos($input, ']');
$len = $closed - ($i+1);
$output .= str_repeat(substr($input, $i+1, $len), $prev);
$i = strpos($input, ']');
}elseif(ctype_digit($char)){
$prev = $char;
}else{
$output .= $char;
}
}
echo $output;
Is there any ways to solving it using this approach or another. Or only can be solved using stack?
Thank you for any idea can help solving this problem!
To solve nested [], you have to decode from the inside out. The solution uses preg_replace_callback until there is nothing left to replace.
function fkdecode($str){
while(true){
$newStr = preg_replace_callback('~(\d+)\[([^\[\]]+)\]~',
function($m){
return str_repeat($m[2],(int)$m[1]);
},
$str);
if($newStr == $str) break;
$str = $newStr;
}
return $str;
}
//test
$inputs = ["4[abc]", // output: abcabcabcabc
"ac3[ab]d", // output: acabababd
"a2[b3[cd]]", // output: abcdcdcdbcdcdcd
];
foreach($inputs as $input){
echo $input.' := '. fkdecode($input)."<br>\n";
}
Output:
4[abc] := abcabcabcabc
ac3[ab]d := acabababd
a2[b3[cd]] := abcdcdcdbcdcdcd
Use strpos() with offset ($i in your case) specified to decode multiple encoded string.
You could've used strlen instead of count. It's to avoid array to string conversion error. Also, you should take into consideration the case when N > 9.
$output = '';
for ($i = 0; $i < strlen($input); $i++) {
$char = $input[$i];//current character
if($char == '['){
$closed = strpos($input, ']', $i);
$len = $closed - ($i+1);
$output .= str_repeat(substr($input, $i+1, $len), $prev);
$i = strpos($input, ']', $i);
}elseif(ctype_digit($char)){
$end = strpos($input, '[', $i);
$len = $end - $i;
$prev = substr($input, $i, $len);
$i = strpos($input, '[', $i) - 1;
}else{
$output .= $char;
}
}
echo $output;
?>
BTW, this doesn't solve the nested []. You could use a stack to solve it. Hint: Check if there's a [ before $closed. Or use this non-O(n) approach.
Related
I have a string like $str.
$str = "00016cam 321254300022cam 321254312315300020cam 32125433153";
I want to split it in array like this. The numbers before 'cam' is the string length.
$splitArray = ["00016cam 3212543", "00022cam 3212543123153", "00020cam 32125433153"]
I have tried following code:
$lengtharray = array();
while ($str != null)
{
$sublength = substr($str, $star, $end);
$star += (int)$sublength; // echo $star."<br>"; // echo $sublength."<br>";
if($star == $total)
{
exit;
}
else
{
}
array_push($lengtharray, $star); // echo
print_r($lengtharray);
}
You can try this 1 line solution
$str = explode('**', preg_replace('/\**cam/', 'cam', $str)) ;
If your string doesn't contain stars then I'm afraid you need to write a simple parser that will:
take characters from the left until it's not numeric
do substr having the length
repeat previous steps on not consumed string
<?php
$input = "00016cam 321254300022cam 321254312315300020cam 32125433153";
function parseArray(string $input)
{
$result = [];
while ($parsed = parseItem($input)) {
$input = $parsed['rest'];
$result[] = $parsed['item'];
}
return $result;
}
function parseItem(string $input)
{
$sLen = strlen($input);
$len = '';
$pos = 0;
while ($pos < $sLen && is_numeric($input[$pos])) {
$len .= $input[$pos];
$pos++;
}
if ((int) $len == 0) {
return null;
}
return [
'rest' => substr($input, $len),
'item' => substr($input, 0, $len)
];
}
var_dump(parseArray($input));
this code works for me. hope helps.
$str = "**00016**cam 3212543**00022**cam 3212543123153**00020**cam 32125433153";
$arr = explode("**", $str);
for ($i=1; $i < sizeof($arr); $i=$i+2)
$arr_final[]=$arr[$i].$arr[$i+1];
I'm trying to parse a string and delete the adjacent letters that are same. I want to return the count of number of deletions and output the resulted string after the deletions are made. Say I have
$str = "aaabbbcc";
As you can see, you need to do 5 deletions to make the adjacent letters not same. The $output string is "abc" and the number of deletions is five.
function str_deletions ($str)
{
$prev = $str[0];
$length = strlen($str);
$deletions = 0;
$output = "";
for ($i=1 ; $i < $length; $i++)
{
if ($str[$i]== $prev)
{
$deletions++;
$prev = $str[$i]; // not sure here ?
}
}
echo $output; // ?
return $deletions;
}
$str = "aabbcc";
echo str_deletions ($str);
EDIT
This is an interview question, I'm not supposed to use any built-in functions like regex or array_count_values
Thanks for your help !
Here is another regex solution. I use a regex to only match a word character that is repeated, and then remove each consecutive repeating character one by one, which allows me to use &$count argument with preg_replace:
count
If specified, this variable will be filled with the number of replacements done.
The regex is
(\w)(?=\1)
See demo. Note you can replace \w with . to match any character but a newline. OR if you need to match only letters, I suggest using '/(\p{L})(?=\1)/u'
See IDEONE demo:
$str = "aaabbbcc";
$cnt = -1;
$result = preg_replace('/(\w)(?=\1)/', "", $str, -1, $cnt);
echo "Result: " . $result . PHP_EOL . "Deletions: " . $cnt;
Output:
Result: abc
Deletions: 5
Regex solution
This is a much simpler way of doing what you're after using preg_replace():
<?php
function str_deletions($str){
$replaced = preg_replace("/(.)\\1+/", "", $str);
$length = strlen($str) - strlen($replaced);
return array("new_word" => $replaced, "chars_replaced" => $length);
}
$str = "aabbcc";
$string_deletions = str_deletions($str);
echo "New String: " . $string_deletions['new_word'] . "\n";
echo "Chars deleted: " . $string_deletions['chars_replaced'] . "\n";
?>
No inbuilt functions
For the purposes of completion (and since you updated your question with more information to say that we can't use regexes because it's an interview question), here's what I'd do:
Using count_chars():
function str_deletions($str){
$string_data['new_word'] = count_chars($str,3);
$string_data['chars_replaced'] = strlen($str) - strlen($string_data['new_word']);
return $string_data;
}
$str = "aabbcc";
echo str_deletions($str);
Note: in this example count_chars(); will return unique chars in a string, not quite remove duplicates (i.e. "aabbccaa" would still yield "abc" as an output) but your question wasn't clear what the interviewer wanted - whether it was truly a remove duplicate question or a unique char question.
Using array_unique():
Slightly slower and a bit more heavy handed:
function str_deletions($str){
$string_array = array_unique(str_split($str));
foreach($string_array as $string_cur){
$string_data['new_word'] .= $string_cur;
}
$string_data['chars_replaced'] = strlen($str) - strlen($string_data['new_word']);
return $string_data;
}
$str = "aabbcc";
echo str_deletions($str);
Note: It's worth pointing out that if I realised it was an interview question, I wouldn't have provided an answer as doing it for you kind of defeats the purpose. Still, with the amount of answers here now and the fact that I've seen something similar to this in an interview, my hope is someone will learn from these.
The basic algorithm (indeed $prev = $str[$i]; isn't at the good place but you wasn't far):
function str_deletion($str) {
$del = 0;
if (1 < $length = strlen($str)) { // $str has more than 1 char
$prev = $str[0];
$output = $prev;
for ($i=1; $i<$length; $i++) {
if ($prev == $str[$i]) {
$del++;
} else {
$prev = $str[$i]; // when different, change the previous character
$output .= $prev; // and append it to the output
}
}
} else {
$output = $str;
}
echo $output;
return $del;
}
I have changed your function
this is not returning both the output string and number of deletions
function str_deletions ($str)
{
$prev = NULL;
$deletions = 0;
$output = "";
$i=0;
while ($i < strlen($str))
{
if (substr($str,$i,1) == $prev)
{
$deletions++;
//$prev = substr($str,$i,1);/*remove this line, no need here as the same stmnt is there after ifelse*/
}else{
$output.=substr($str,$i,1);
}
$prev = substr($str,$i,1);
$i++;
}
$arr = array(
'output'=>$output,
'deletions'=>$deletions
);
return $arr;
}
$str = "aaabbcc";
print_r(str_deletions ($str));
output for above function call is
Array ( [output] => abc [deletions] => 4 )
Solved with no external function except count;
$str="aaavvvffccca";
$count = strlen($str);
for($i=0;$i<$count;$i++){
$array[]=$str[$i];
}
$del =0;
for($i=0;$i<$count;$i++){
$next=isset($array[$i+1])?$array[$i+1]:null;
if($array[$i]==$next)
{
$del++;
}
else
{
$newarray[]=$array[$i];
}
}
echo "Filter Text:". implode('',$newarray);
echo"Total Deleted:".$del;
The straight forward solution to find out the number of deletions can be
If there are N consecutive same characters delete N-1 out of those N characters.
function str_likes($str)
{
$length = strlen($str);
$del = 0;
for ($i=0 ; $i < $length ; $i++)
{
if ($str[$i] == $str[$i+1])
{
$del++;
}
}
return $del;
}
$str = "aabbccaaa";
echo str_likes($str); //4
Some time ago during a job interview I got the task to reverse a string in PHP without using strrev.
My first solution was something like this:
$s = 'abcdefg';
$temp = '';
for ($i = 0, $length = mb_strlen($s); $i < $length; $i++) {
$temp .= $s{$length - $i - 1};
}
var_dump($temp);
// outputs string(7) "gfedcba"
then they asked me if I could do this without doubling the memory usage (not using the $temp variable or any variable to copy the reversed string to) and I failed.
This kept bugging me and since then I tried to solve this multiple times but I constantly failed.
My latest try looks like this:
$s = 'abcdefg';
for ($i = 0, $length = mb_strlen($s); $i < $length; $i++) {
$s = $s{$i * 2} . $s;
}
var_dump($s);
// outputs string(14) "gfedcbaabcdefg"
It's not a solution to chop off "abcdefg" after the loop because then I would still double the amount of memory used. I need to remove the last character in every iteration of the loop.
I tried to use mb_substr like this:
$s = 'abcdefg';
for ($i = 0, $length = mb_strlen($s); $i < $length; $i++) {
$s = $s{$i * 2} . mb_substr($s, $length - $i - 1, 1);
}
var_dump($s);
but it only gives me Uninitialized string offset errors.
This is where I'm stuck (again). I tried googling but all the solutions I found either echo the characters directly or use a temporary variable.
I also found the Question PHP String reversal without using extra memory but there's no answer that fits my needs.
That's an interesting one.
Here's something I just came up with:
$s = 'abcdefghijklm';
for($i=strlen($s)-1, $j=0; $j<$i; $i--, $j++) {
list($s[$j], $s[$i]) = array($s[$i], $s[$j]);
}
echo $s;
list() can be used to assign a list of variables in one operation. So what I am doing is simply swapping characters (starting with first and last, then second-first and second-last and so on, till it reaches the middle of the string)
Output is mlkjihgfedcba.
Not using any other variables than $s and the counters, so I hope that fits your criteria.
You can use the fact that in PHP a string can be thought of as an array of characters.
Then basically what you want to do is to replace each character $i on the left side of the middle of the string with the character $j on the right side of the middle with the same distance.
For example, in a string of seven characters the middle character is on position 3. The character on position 0 (distance 3) needs to be swapped with the character on position 6 (3 + 3), the character on position 1 (distance 2) needs to be swapped with the character on position 5 (3 + 2), etc.
This algorithm can be implemented as follows:
$s = 'abcdefg';
$length = strlen($s);
for ($i = 0, $j = $length-1; $i < ($length / 2); $i++, $j--) {
$t = $s[$i];
$s[$i] = $s[$j];
$s[$j] = $t;
}
var_dump($s);
$string = 'abc';
$reverted = implode(array_reverse(str_split($string)));
You could use the XOR swap trick.
function rev($str) {
$len = strlen($str);
for($i = 0; $i < floor($len / 2); ++$i) {
$str[$i] = $str[$i] ^ $str[$len - $i - 1];
$str[$len - $i - 1] = $str[$i] ^ $str[$len - $i - 1];
$str[$i] = $str[$i] ^ $str[$len - $i - 1];
}
return $str;
}
print rev("example");
Try this:
$s = 'abcdefg';
for ($i = strlen($s)-1; $i>=0; $i--) {
$s .= $s[$i];
$s[$i] = NULL;
}
var_dump(trim($s));
Here it is PHP7 version of this:
echo "\u{202E}abcdefg"; // outs: gfedcba
PHP strings are kinda-sorta mutable, but due to copy-on-write it's very difficult to modify them in-place without a copy being made. Some of the above solutions work, but only because they're stand-alone; some already fail because they define a function without a pass-by-reference argument. To get the code to actually operate in-place in a larger program, you'd need to pay careful attention to assignments, function arguments, and scopes.
Example:
$string1 = 'abc';
$string2 = $string1;
$string1[0] = 'b';
print("$string1, $string2");
> "abc, bbc"
I suppose that if between initializing the variable and modifying it you only ever used by-reference assignments (&=) and reference arguments (function rev(&$string)) (or assign the string to an object property initially, and then never assign it to any other variable), you might be able to change the original value of the string without making any copies. That's a bit ridiculous, however, and I'd assume that the interviewer who came up with that question didn't know about copy-on-write.
This isn't quite the same as immutability in other languages, by the way, because it applies to arrays too:
$a = [0, 1, 2];
$b = $a;
$b[0] = 1;
print(implode($a).implode($b));
> "012112"
To sum up, all types (except for objects as of PHP5) are assigned with copy-on-write unless you specifically use the &= operator. The assignment doesn't copy them, but unlike most other languages (C, Java, Python...) that either change the original value (arrays) or don't allow write access at all (strings), PHP will silently create a copy before making any changes.
Of course, if you switched to a language with more conventional pointers and also switched to byte arrays instead of strings, you could use XOR to swap each pair of characters in place:
for i = 0 ... string.length / 2:
string[i] ^= string[string.length-1-i]
string[string.length-1-i] ^= string[i]
string[i] ^= string[string.length-1-i]
Basically #EricBouwers answer, but you can remove the 2nd placeholder variable $j
function strrev2($str)
{
$len = strlen($str);
for($i=0;$i<$len/2;$i++)
{
$tmp = $str[$i];
$str[$i] = $str[$len-$i-1];
$str[$len-$i-1] = $tmp;
}
return $str;
}
Test for the output:
echo strrev2("Hi there!"); // "!ereht iH"
echo PHP_EOL;
echo strrev2("Hello World!"); // "!dlroW olleH"
This will go through the list and stop halfway, it swaps the leftmost and rightmost, and works it's way inward, and stops at the middle. If odd numbered, the pivot digit is never swapped with itself, and if even, it swaps the middle two and stops. The only extra memory used is $len for convenience and $tmp for swapping.
If you want a function that doesn't return a new copy of the string, but just edits the old one in place you can use the following:
function strrev3(&$str)
{
$len = strlen($str);
for($i=0;$i<$len/2;$i++)
{
$tmp = $str[$i];
$str[$i] = $str[$len-$i-1];
$str[$len-$i-1] = $tmp;
}
}
$x = "Test String";
echo $x; // "Test String"
strrev3($x);
echo PHP_EOL;
echo $x; // "gnirtS tseT"
Using &$str passes a direct pointer the the string for editing in place.
And for a simpler implementation like #treegardens, you can rewrite as:
$s = 'abcdefghijklm';
$len = strlen($s);
for($i=0; $i < $len/2; $i++) {
list($s[$i], $s[$len-$i-1]) = array($s[$len-$i-1], $s[$i]);
}
echo $s;
It has the similar logic, but I simplified the for-loop quite a bit.
Its Too Simple
//Reverse a String
$string = 'Basant Kumar';
$length = strlen($string);
for($i=$length-1;$i >=0;$i--){
echo $string[$i];
}
Here is my code to solve your problem
<?php
$s = 'abcdefg';
for ($i = 0, $length = mb_strlen($s); $i < $length; $i++) {
$s = $s{$i}.mb_substr($s,0,$i).mb_substr($s,$i+1);
}
var_dump($s);
?>
You could also use a recursion to reverse the string. Something like this for example:
function reverse($s) {
if(strlen($s) === 1) return $s;
return substr($s, strlen($s)-1) . reverse(substr($s , 0, strlen($s)-1));
}
What you do here is actually returning the last character of the string and then calling again the same function with the substring that contains the initial string without the last character. When you reach the point when your string is just one character then you end the recursion.
You can use this code to reverse a string without using the reserved function in php.
Code:
<?php
function str_rev($y)// function for reversing a string by passing parameters
{
for ($x = strlen($y)-1; $x>=0; $x--) {
$y .= $y[$x];
$y[$x] = NULL;
}
echo $y;
}
str_rev("I am a student");
?>
Output:
tneduts a ma I
In the above code, we have passed the value of the string as the parameter.We have performed the string reversal using for loop.
you could use substr with negative start.
Theory & Explanation
you can start with for loop with counter from 1 to length of string, and call substr inside iteration with counter * -1 (which will convert the counter into negative value) and length of 1.
So for the first time counter would be 1 and by multiplying with -1 will turn it to -1
Hence substr('abcdefg', -1, 1); will get you g
and next iteration substr('abcdefg', -2, 1); will get you f
and substr('abcdefg', -3, 1); will get you e
and so on ...
Code
$str = 'abcdefghijklmnopqrstuvwxyz';
for($i=1; $i <= strlen($str); $i++) {
echo substr($str, $i*-1, 1);
}
In Action: https://eval.in/583208
public function checkString($str){
if(!empty($str)){
$i = 0;
$str_reverse = '';
while(isset($str[$i])){
$strArr[] = $str[$i];
$i++;
}
for($j = count($strArr); $j>= 0; $j--){
if(isset($strArr[$j])){
$str_reverse .= $strArr[$j];
}
}
if($str == $str_reverse){
echo 'It is a correct string';
}else{
echo 'Invalid string';
}
}
else{
echo 'string not found.';
}
}
//Reverse String word by word
$str = "Reverse string word by word";
$i = 0;
while ($d = $str[$i]) {
if($d == " ") {
$out = " ".$temp.$out;
$temp = "";
}
else
$temp .= $d;
$i++;
}
echo $temp.$out;
The following solution is very simple, but it does the job:
$string = 'Andreas';
$reversedString = '';
for($i = mb_strlen($string) - 1; $i >= 0; $i--){
$reversedString .= $string[$i];
}
var_dump($reversedString) then results: string(7) "saerdnA"
<?php
$value = 'abcdefg';
$length_value = strlen($value);
for($i = $length_value-1; $i >=0 ;$i--){
echo $value[$i];
}
?>
you can try this..
$string = "NASEEM";
$total_word = strlen($string);
for($i=0; $i<=$total_word; $i++)
{
echo substr($string,$total_word-$i,1);
}
i have used some built in function but without str_rev function .
<?php
$text = "red";
$arr = str_split($text);
$rev_text = array_reverse($arr);
echo join(" ",$rev_text);
?>
Try This
<?php
$str="abcde";
for($i=strlen($str)-1;$i>=0;$i--){
echo $str[$i];
}
?>
output
edcba
This is my solution to solve this.
$in = 'This is a test text';
$out = '';
// find string length
$len = strlen($in);
// loop through it and print it reverse
for ( $i = $len - 1; $i >=0;$i-- )
{
$out = $out.$in[$i];
}
echo $out;
Reverse string using recursion function.
$reverseString = '';
function Reverse($str, $len)
{
if ($len == 0) {
return $GLOBALS['reverseString'];
} else {
$len--;
$GLOBALS['reverseString'] .= $str[$len];
return Reverse($str, $len);
}
}
$str = 'Demo text';
$len = strlen($str);
echo Reverse($str, $len)
Try this
$warn = 'this is a test';
$i=0;
while(#$warn[$i]){
$i++;}
while($i>0)
{
echo $warn[$i-1]; $i--;
}
How I cut the extra 0 string from those sample.
current string: 0102000306
required string: 12036
Here a 0 value have in front of each number. So, i need to cut the extra all zero[0] value from the string and get my expected string. It’s cannot possible using str_replace. Because then all the zero will be replaced. So, how do I do it?
Using a regex:
$result = preg_replace('#0(.)#', '\\1', '0102000306');
Result:
"12036"
Using array_reduce:
$string = array_reduce(str_split('0102000306', 2), function($v, $w) { return $v.$w[1]; });
Or array_map+implode:
implode('',array_map('intval',str_split('0102000306',2)));
$currentString = '0102000306';
$length = strlen($currentString);
$newString = '';
for ($i = 0; $i < $length; $i++) {
if (($i % 2) == 1) {
$newString .= $currentString{$i};
}
}
or
$currentString = '0102000306';
$tempArray = str_split($currentString,2);
$newString = '';
foreach($tempArray as $val) {
$newString .= substr($val,-1);
}
It's not particularly elegant but this should do what you want:
$old = '0102000306';
$new = '';
for ($i = 0; $i < strlen($old); $i += 2) {
$new .= $old[$i+1];
}
echo $new;
This question already has answers here:
Reverse the letters in each word of a string
(6 answers)
Closed 1 year ago.
This task has already been asked/answered, but I recently had a job interview that imposed some additional challenges to demonstrate my ability to manipulate strings.
Problem: How to reverse words in a string? You can use strpos(), strlen() and substr(), but not other very useful functions such as explode(), strrev(), etc.
Example:
$string = "I am a boy"
Answer:
I ma a yob
Below is my working coding attempt that took me 2 days [sigh], but there must be a more elegant and concise solution.
Intention:
1. get number of words
2. based on word count, grab each word and store into array
3. loop through array and output each word in reverse order
Code:
$str = "I am a boy";
echo reverse_word($str) . "\n";
function reverse_word($input) {
//first find how many words in the string based on whitespace
$num_ws = 0;
$p = 0;
while(strpos($input, " ", $p) !== false) {
$num_ws ++;
$p = strpos($input, ' ', $p) + 1;
}
echo "num ws is $num_ws\n";
//now start grabbing word and store into array
$p = 0;
for($i=0; $i<$num_ws + 1; $i++) {
$ws_index = strpos($input, " ", $p);
//if no more ws, grab the rest
if($ws_index === false) {
$word = substr($input, $p);
}
else {
$length = $ws_index - $p;
$word = substr($input, $p, $length);
}
$result[] = $word;
$p = $ws_index + 1; //move onto first char of next word
}
print_r($result);
//append reversed words
$str = '';
for($i=0; $i<count($result); $i++) {
$str .= reverse($result[$i]) . " ";
}
return $str;
}
function reverse($str) {
$a = 0;
$b = strlen($str)-1;
while($a < $b) {
swap($str, $a, $b);
$a ++;
$b --;
}
return $str;
}
function swap(&$str, $i1, $i2) {
$tmp = $str[$i1];
$str[$i1] = $str[$i2];
$str[$i2] = $tmp;
}
$string = "I am a boy";
$reversed = "";
$tmp = "";
for($i = 0; $i < strlen($string); $i++) {
if($string[$i] == " ") {
$reversed .= $tmp . " ";
$tmp = "";
continue;
}
$tmp = $string[$i] . $tmp;
}
$reversed .= $tmp;
print $reversed . PHP_EOL;
>> I ma a yob
Whoops! Mis-read the question. Here you go (Note that this will split on all non-letter boundaries, not just space. If you want a character not to be split upon, just add it to $wordChars):
function revWords($string) {
//We need to find word boundries
$wordChars = 'abcdefghijklmnopqrstuvwxyz';
$buffer = '';
$return = '';
$len = strlen($string);
$i = 0;
while ($i < $len) {
$chr = $string[$i];
if (($chr & 0xC0) == 0xC0) {
//UTF8 Characer!
if (($chr & 0xF0) == 0xF0) {
//4 Byte Sequence
$chr .= substr($string, $i + 1, 3);
$i += 3;
} elseif (($chr & 0xE0) == 0xE0) {
//3 Byte Sequence
$chr .= substr($string, $i + 1, 2);
$i += 2;
} else {
//2 Byte Sequence
$i++;
$chr .= $string[$i];
}
}
if (stripos($wordChars, $chr) !== false) {
$buffer = $chr . $buffer;
} else {
$return .= $buffer . $chr;
$buffer = '';
}
$i++;
}
return $return . $buffer;
}
Edit: Now it's a single function, and stores the buffer naively in reversed notation.
Edit2: Now handles UTF8 characters (just add "word" characters to the $wordChars string)...
My answer is to count the string length, split the letters into an array and then, loop it backwards. This is also a good way to check if a word is a palindrome. This can only be used for regular string and numbers.
preg_split can be changed to explode() as well.
/**
* Code snippet to reverse a string (LM)
*/
$words = array('one', 'only', 'apple', 'jobs');
foreach ($words as $d) {
$strlen = strlen($d);
$splits = preg_split('//', $d, -1, PREG_SPLIT_NO_EMPTY);
for ($i = $strlen; $i >= 0; $i=$i-1) {
#$reverse .= $splits[$i];
}
echo "Regular: {$d}".PHP_EOL;
echo "Reverse: {$reverse}".PHP_EOL;
echo "-----".PHP_EOL;
unset($reverse);
}
Without using any function.
$string = 'I am a boy';
$newString = '';
$temp = '';
$i = 0;
while(#$string[$i] != '')
{
if($string[$i] == ' ') {
$newString .= $temp . ' ';
$temp = '';
}
else {
$temp = $string[$i] . $temp;
}
$i++;
}
$newString .= $temp . ' ';
echo $newString;
Output: I ma a yob