How to reverse a string and replace chars? - php

I have been asked by an interviewer for a test:
$string = "This is sample string";
// Output: "string_sample_is_This";
what does this question mean..?
I assumed that he was asking about a simple echo, am I right or would he expected something else from me ?
<?php
$string = "This is sample string";
echo $string;
?>

He definetly asked for something else ...
<?php
$string = explode(" ","This is sample string");
$string = array_reverse($string);
$string = implode("_",$string);
echo $string;
?>
More :
PHP explode()
PHP array_reverse()
PHP implode()

That looks more like you are being asked to reverse the order of the tokens in the string and replace the delimiter from single spaces to the _ character. I would assume that or something similar to such was being asked.

No he told to reverse the sentence and echo the string.
<?php
$string = "This is sample string";
$string1 = '';
$string_array = explode(' ',$string);
$count = count($string_array) - 1;
for($i=$count; $i>=0; $i--)
{
if($i == 0)
{
$string1 .= $string_array[$i];
}
else
{
$string1 .= $string_array[$i]."_";
}
}
echo $string1;
?>

Related

Php search replacer

I have a search String: $str (Something like "test"), a wrap string: $wrap (Something like "|") and a text string: $text (Something like "This is a test Text").
$str is 1 Time in $text. What i want now is a function that will wrap $str with the wrap defined in $wrap and output the modified text (even if $str is more than one time in $text).
But it shall not output the whole text but just 1-2 of the words before $str and then 1-2 of the words after $str and "..." (Only if it isn`t the first or last word). Also it should be case insensitive.
Example:
$str = "Text"
$wrap = "<span>|</span>"
$text = "This is a really long Text where the word Text appears about 3 times Text"
Output would be:
"...long <span>Text</span> where...word <span>Text</span> appears...times <span>Text</span>"
My Code (Obviusly doesnt works):
$tempar = preg_split("/$str/i", $text);
if (count($tempar) <= 2) {
$result = "... ".substr($tempar[0], -7).$wrap.substr($tempar[1], 7)." ...";
} else {
$amount = substr_count($text, $str);
for ($i = 0; $i < $amount; $i++) {
$result = $result.".. ".substr($tempar[$i], -7).$wrap.substr($tempar[$i+1], 0, 7)." ..";
}
}
If you have a tipp or a solution dont hesitate to let me know.
I have taken your approach and made it more flexible. If $str or $wrap changes you could have escaping issues within the regex pattern so I have used preg_quote.
Note that I added $placeholder to make it clearer, but you can use $placeholder = "|" if you don't like [placeholder].
function wrapInString($str, $text, $element = 'span') {
$placeholder = "[placeholder]"; // The string that will be replaced by $str
$wrap = "<{$element}>{$placeholder}</{$element}>"; // Dynamic string that can handle more than just span
$strExp = preg_quote($str, '/');
$matches = [];
$matchCount = preg_match_all("/(\w+\s+)?(\w+\s+)?({$strExp})(\s+\w+)?(\s+\w+)?/i", $text, $matches);
$response = '';
for ($i = 0; $i < $matchCount; $i++) {
if (strlen($matches[1][$i])) {
$response .= '...';
}
if (strlen($matches[2][$i])) {
$response .= $matches[2][$i];
}
$response .= str_replace($placeholder, $matches[3][$i], $wrap);
if (strlen($matches[4][$i])) {
$response .= $matches[4][$i];
}
if (strlen($matches[5][$i]) && $i == $matchCount - 1) {
$response .= '...';
}
}
return $response;
}
$text = "text This is a really long Text where the word Text appears about 3 times Text";
string(107) "<span>text</span> This...long <span>text</span> where...<span>text</span> appears...times <span>text</span>"
To make the replacement case insensitive you can use the i regex option.
If I understand your question correct, just a little bit of implode and explode magic needed
$text = "This is a really long Text where the word Text appears about 3 times Text";
$arr = explode("Text", $text);
print_r(implode('<span>Text</span>', $arr));
If you specifically need to render the span tags using HTML, just write it that way
$arr = explode("Text", $text);
print_r(implode('<span>Text</span>', $arr));
Use patern below to get your word and 1-2 words before and after
/((\w+\s+){1,2}|^)text((\s+\w+){1,2}|$)/i
demo
In PHP code it can be:
$str = "Text";
$wrap = "<span>|</span>";
$text = "This is a really long Text where the word Text appears about 3 times Text";
$temp = str_replace('|', $str, $wrap); // <span>Text</span>
// find patern and 1-2 words before and after
// (to make it casesensitive, delete 'i' from patern)
if(preg_match_all('/((\w+\s+){1,2}|^)text((\s+\w+){1,2}|$)/i', $text, $match)) {
$res = array_map(function($x) use($str, $temp) { return '... '.str_replace($str, $temp, $x) . ' ...';}, $match[0]);
echo implode(' ', $res);
}

How to remove 4th letter in string using PHP?

How to remove 4th letter in string using PHP ?
I use this code.
<?php
$str = "1234567890";
$str2 = mb_substr($str, 4);
echo $str2;
?>
But it's will echo 567890
I want to echo 123567890 remove 4 from string.
How can i do ?
You can try substr_replace for this. Here we are replacing 4 which is at 3rd index.
Try this code snippet here
<?php
$str = "1234567890";
echo substr_replace($str, "", 3,1);
try setting the 3rd index to null
<?php
$str = "1234567890";
$str[3] = null;
echo $str;
try with below sulution:
$str = '1234567890';
$str_arr = str_split($str);
unset($str_arr[3]);
echo implode('', $str_arr);
output:
123567890
There are multiple ways of performing any operations on string variables in php
// can be used for printing purpose
$str = "1234567890";
echo substr($str,0,3).substr($str,4);
// actual replacement of string
$str = "1234567890";
echo substr_replace($str, "", 3,1);

How to find out if there is any redundant word in string in php?

I need to find out if there are any redundant words in string or not .Is there any function that can provide me result in true/false.
Example:
$str = "Hey! How are you";
$result = redundant($str);
echo $result ; //result should be 0 or false
But for :
$str = "Hey! How are are you";
$result = redundant($str);
echo $result ; //result should be 1 or true
Thank you
You could use explode to generate an array containing all words in your string:
$array = explode(" ", $str);
Than you could prove if the arrays contains duplicates with the function provided in this answer:
https://stackoverflow.com/a/3145660/5420511
I think this is what you are trying to do, this splits on punctuation marks or whitespaces. The commented out lines can be used if you want the duplicated words:
$str = "Hey! How are are you?";
$output = redundant($str);
echo $output;
function redundant($string){
$words = preg_split('/[[:punct:]\s]+/', $string);
if(max(array_count_values($words)) > 1) {
return 1;
} else {
return 0;
}
//foreach(array_count_values($words) as $word => $count) {
// if($count > 1) {
// echo '"' . $word . '" is in the string more than once';
// }
//}
}
References:
http://php.net/manual/en/function.array-count-values.php
http://php.net/manual/en/function.max.php
http://php.net/manual/en/function.preg-split.php
Regex Demo: https://regex101.com/r/iH0eA6/1

i want text and numeric part from the string in php

i have one string
$str ='california 94063';
now i want california and 94063 both in diferent variable.
string can be anything
Thanks in advance....
How about
$strings = explode(' ', $str);
Assuming that your string has ' ' as a separator.
Then, if you want to find the numeric entries of the $strings array, you can use is_numeric function.
Do like this
list($str1,$str2)=explode(' ',$str);
echo $str2;
If your string layout is always the same (say: follows a given format) then I'd use sscanf (http://www.php.net/manual/en/function.sscanf.php).
list($str, $number) = sscanf('california 94063, "%str %d");
<?php
$str ='california 94063';
$x = preg_match('(([a-zA-Z]*) ([0-9]*))',$str, $r);
echo 'String Part='. $r[1];
echo "<br />";
echo 'Number Part='.$r[2];
?>
If text pattern can be changed then I found this solution
Source ::
How to separate letters and digits from a string in php
<?php
$string="94063 california";
$chars = '';
$nums = '';
for ($index=0;$index<strlen($string);$index++) {
if(isNumber($string[$index]))
$nums .= $string[$index];
else
$chars .= $string[$index];
}
echo "Chars: -".trim($chars)."-<br>Nums: -".trim($nums)."-";
function isNumber($c) {
return preg_match('/[0-9]/', $c);
}
?>

PHP String Replace/Append

I am trying out a Logic in strings but facing difficulties in string manipulation functions. Which function will be good for this below approach:
My String is "Hello" I want to add "------------------" after the first string that is "Hello--------------" and the length of the string should be 20 after the string manipulation.
I want to add "------------------" to the string to make it 20 length.
In other words: Hello+Underscores
If the string length is too much we can trim the string.
Below is the code which I tried.
<?php
$challenge = 'hello';
$length = strlen($challenge);
$i= $length +1;
$challenge=substr($challenge,0,$i);
echo $challenge.'<br>';
?>
I tried string concatenation but I am sure I cant use it in this logic, I think the string adding should be done with preg_replace.
Can some one give a good advice on it!
str-pad is the easiest way to achieve your task and code sample as follows.
<?php
$input = "Alien";
echo str_pad($input, 10); // produces "Alien "
echo str_pad($input, 10, "-=", STR_PAD_LEFT); // produces "-=-=-Alien"
echo str_pad($input, 10, "_", STR_PAD_BOTH); // produces "__Alien___"
echo str_pad($input, 6 , "___"); // produces "Alien_"
?>
Just use str_pad.
$input = 'hello';
$output = str_pad($input, 20, '_');
echo $output;
demo: http://ideone.com/0EPoV2
Here you go
<?php
$string = "anything";
echo substr($string."------------------------------------------",0,20);
?>
Just use the first 20 chars of your string and ------------------------
Edit based on new requirement not given in original question for some reason.
<?php
$string = "anything";
$newstring = substr($string."------------------------------------------",0,20);
echo $newstring."whatever you want to add at end";
?>
Try this
<?php
$input = "HELLO";
echo str_pad($input, 10, "----", STR_PAD_RIGHT);
?>
here $input is string and 10 is length of char added STR_PAD_RIGHT is position
View this link PHP.net
$str = 'Hello';
$str .= "_";
while(strlen($str) <= 20){
$str .= "-";
}
echo $str;
try this code
$challenge = 'hello';
$length = strlen($challenge);
if($length < 20){
$limit = 20-$length;
for($i=0;$i<$limit;$i++){
$challenge .= '_';
}
}
echo $challenge;

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