How can I insert a string into a string after specific characters? - php

$string = 'blue*green-yellow-orange/rosa*white+lila';
$calcSigns = '+-*/';
$addstring = 'color1';
Whenever there is a calculation Sign I want to add after the calculation sign the string "color-1".
The result, that I am trying to achieve is:
blue*color-1green-color-1yellow-color-1orange/color-1rosa*color-1white+color-1lila
This is my approach:
$result = substr_replace($string, $addstring, $calcSigns);
But I do not get the correct result.

substr_replace() would make it tricky to preserve the current operation character while replacing. You could instead loop through each character and create a new string out of it.
<?php
$len = strlen( $string );
$new_string = '';
for( $i=0; $i<$len; ++$i ) {
$new_string .= $string[$i];
if( in_array( $string[$i], ['+','-','*','/'] ) ) {
$new_string .= $addstring;
}
}
echo $new_string;
?>
Demo: https://3v4l.org/P5tVr
Update:
So, if a operation character is immediately succeeded by a digit and if you want to skip it, and insert addString otherwise, it would look something like below:
<?php
$string = 'blue+yellow*3-grey+orange';
$calcSigns = '+-*/';
$addstring = 'color1';
$len = strlen($string);
$new_string = '';
for($i=0;$i<$len;++$i){
$new_string .= $string[$i];
if(in_array($string[$i],['+','-','*','/'])){
if($i + 1 < $len && is_numeric($string[$i + 1])) continue;
$new_string .= $addstring;
}
}
echo $new_string;
Demo: https://3v4l.org/uQobj

Related

How to capitalize first letter of word in php without ucfirst() function

I am trying to capitalize the first letter of word in php without using ucfirst() function But i am not able do it , but i am struggling with this. Please tell me its answer.
<?php
$str ="the resources of earth make life possible on it";
$str[0] = chr(ord($str[0])-32);
$length = strlen($str);
for($pos=0; $pos<$length; $pos++){
if($str[$pos]==' '){
$str[$pos+1] = chr(ord($str[$pos+1])-32);
}
}
echo $str;
?>
Without using the function ucfirst, you can do it like this:
$firstLetter = substr($word, 0, 1);
$restOfWord = substr($word, 1);
$firstLetter = strtoupper($firstLetter);
$restOfWord = strtolower($restOfWord);
print "{$firstLetter}{$restOfWord}\n";
To do it for each word, use explode(' ', $string) to get an array of words, or preg_split('#\\s+#', $string, -1, PREG_SPLIT_NO_EMPTY) for better results.
I would advise against just subtracting 32 from the first character of the next word:
you do not know it is a letter
you do not know it isn't already capitalized
you do not know it exists
you do not know it is not another space
At the very least check that its ord() value lies between ord('A') and ord('Z').
To do this all without case-changing functions, you'd do
$text = implode(' ',
array_map(
function($word) {
$firstLetter = substr($word, 0, 1);
if ($firstLetter >= 'a' && $firstLetter <= 'z') {
$firstLetter = chr(ord($firstLetter)-32);
}
$restOfWord = substr($word, 1);
$len = strlen($restOfWord);
for ($i = 0; $i < $len; $i++) {
if ($restOfWord[$i] >= 'A' && $restOfWord[$i] <= 'Z') {
$restOfWord[$i] = chr(ord(restOfWord[$i])+32);
}
}
return $firstLetter . $restOfWord;
},
preg_split('#\\s+#', $originalText, -1, PREG_SPLIT_NO_EMPTY)
)
);
as such...
$str ="the resources of earth make life possible on it";
$words=array_map(static fn($a) => ucfirst($a), explode(' ', $str));
echo implode(' ', $words);
with ord and chr
$ordb=ord('b'); //98
$capitalB=chr(98-32); //B
$ordA=ord('a'); //97
$caiptalA=chr(97-32); //A
//so
function capitalize(string $word)
{
$newWord = '';
$previousCharIsEmpty = true;
$length = strlen($word);
for ($a = 0; $a < $length; $a++) {
if ($word[$a] === ' ') {
$newWord .= ' ';
$previousCharIsEmpty = true;
} else {
if ($previousCharIsEmpty === true) {
$ord = ord($word[$a]);
$char = chr($ord - 32);
$newWord .= $char;
$previousCharIsEmpty = false;
} else {
$newWord .= $word[$a];
}
$previousCharIsEmpty = false;
}
return $newWord;
}
$word = 'this for example by dilo abininyeri';
echo capitalize($word);
and output
This For Example By Dilo Abininyeri
We cannot do this without any function. We have to use some function. Like you have applied the for-loop and for strlen function.
<?php
$str ="the resources of earth make life possible on it";
$str[0] = chr(ord($str[0])-32);
$length = strlen($str);
for($pos=0; $pos<$length; $pos++){
if($str[$pos]==' '){
$str[$pos+1] = chr(ord($str[$pos+1])-32);
}
}
echo $str;
?>

Separate alphabets and numbers from a string

$str = 'ABC300';
How I can get values like
$alphabets = "ABC";
$numbers = 333;
I have a idea , first remove numbers from the string and save in a variable. then remove alphabets from the $str variable and save. try the code
$str = 'ABC300';
$alf= trim(str_replace(range(0,9),'',$str));//removes number from the string
$number = preg_replace('/[A-Za-z]+/', '', $str);// removes alphabets from the string
echo $alf,$number;// your expected output
Try something like this (it's not that fast)...
$string = "ABCDE3883475";
$numbers = "";
$alphabets = "";
$strlen = strlen($string);
for($i = 0; $i <= $strlen; $i++) {
$char = substr($string, $i, 1);
if(is_numeric($char)) {
$numbers .= $char;
} else {
$alphabets .= $char;
}
}
Then all numbers should be in $numbers and all alphabetical characters should be in $alphabets ;)
https://3v4l.org/Xh4FR
A way to do that is to find all digits and use the array to replace original string with the digits inside.
For example
function extractDigits($string){
preg_match_all('/([\d]+)/', $string, $match);
return $match[0];
}
$str = 'abcd1234ab12';
$digitsArray = extractDigits($str);
$allAlphas = str_replace($digitsArray,'',$str);
$allDigits = '';
foreach($digitsArray as $digit){
$allDigits .= $digit;
}

delete the repetetion letters in a string php

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

Truncating a string after x amount of charcters

I have a string that that is an unknown length and characters.
I'd like to be able to truncate the string after x amount of characters.
For example from:
$string = "Hello# m#y name # is Ala#n Colem#n"
$character = "#"
$x = 4
I'd like to return:
"Hello# m#y name # is Ala#"
Hope I'm not over complicating things here!
Many thanks
I'd suggest explode-ing the string on #, then getting the 1st 4 elements in that array.
$string = "Hello# m#y name # is Ala#n Colem#n";
$character = "#";
$x = 4;
$split = explode($character, $string);
$split = array_slice($split, 0, $x);
$newString = implode($character, $split).'#';
function posncut( $input, $delim, $x ) {
$p = 0;
for( $i = 0; $i < $x; ++ $i ) {
$p = strpos( $input, $delim, $p );
if( $p === false ) {
return "";
}
++ $p;
}
return substr( $input, 0, $p );
}
echo posncut( $string, $character, $x );
It finds each delimiter in turn (strpos) and stops after the one you're looking for. If it runs out of text first (strpos returns false), it gives an empty string.
Update: here's a benchmark I made which compares this method against explode: http://codepad.org/rxTt79PC. Seems that explode (when used with array_pop instead of array_slice) is faster.
Something along these lines:
$str_length = strlen($string)
$character = "#"
$target_count = 4
$count = 0;
for ($i = 0 ; $i<$str_length ; $i++){
if ($string[$i] == $character) {
$count++
if($count == $target_count) break;
}
}
$result = sub_str($string,0,$i)

cut particular pointed string using php

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;

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