How to limit string length in PHP ?

A string is a sequence of characters in PHP. The length of the string can be limited in PHP using various in-built functions, wherein the string character count can be restricted. 

Using for loop

The str_split() function can be used to convert the specified string into the array object. The array elements are individual characters stored at individual indices. 

str_split($string)

Parameters: 

• $string - The string to split into array

Example: A for loop iteration is performed over the array object until the desired length. The characters are displayed until the length is equivalent to the desired number of characters. 

<?php
    $string = "Geeks for geeks is fun";
    echo("Original String : ");

    echo($string . "\n");
    echo("Modified String : ");

    $arr = str_split($string);

    for($i = 0; $i < 10; $i++) {
        print($arr[$i]);
    }
?>

Original String : Geeks for geeks is fun
Modified String : Geeks for 

Using mb_strimwidth() function

The mb_strimwidth function is used to get truncated string with specified width. It takes as input the string and the required number of characters. The characters after it are appended with an "!!" string. It returns the string with the trimmed length. 

mb_strimwidth(string, start, width, trim_pt)

Parameters: 

• string - The string which is to be trimmed.
• start - The start position offset.
• width - The desired trim length.
• trim_pt - The string that can be added to truncate the length of string with.

Example:

<?php
    // Declaring original string
    $string = "Geeks for geeks is fun";
    echo("Original String : ");
    echo($string . "\n");

    // Trimming length of string
    $new_string =  mb_strimwidth($string, 0, 11, "!!");
    print("Modified String : ");
    print($new_string);
?>

Output

Original String : Geeks for geeks is fun
Modified String : Geeks for!!

Using substr() method

The substr() function can be used to extract the specified string within the specified limits. The starting and ending indexes are specified and the equivalent number of characters between the start and end length are extracted. 

substr(string, start, end)

Parameters: 

• string - The string to extract the substring from.
• start - The starting index to extract the string from.
• end - The ending index to extract the string.

Example:

<?php
    $string = "Geeks for geeks is fun";
    echo("Original String : ");

    echo($string . "\n");
    echo("Modified String : ");

    if (strlen($string) > 10)
       $new_string = substr($string, 0, 10) . '!!!';
    echo($new_string . "\n");
?>

Output:

Original String : Geeks for geeks is fun
Modified String : Geeks for !!!

Using Regular Expressions with preg_match()

Using preg_match() with a regular expression, you can limit the length of a string by matching the first few characters. The pattern /.{0,5}/ captures up to the first 5 characters.

Example:

<?php
    // Declaring original string
    $string = "Geeks for geeks is fun";
    echo("Original String : ");
    echo($string . "\n");

    // Trimming length of string using regular expressions
    preg_match('/^.{0,11}/', $string, $matches);
    $new_string = $matches[0] . "!!";

    print("Modified String : ");
    print($new_string);
?>

Original String : Geeks for geeks is fun
Modified String : Geeks for g!!

Using substr_replace() for truncation with ellipsis

Using substr_replace()` in PHP truncates strings by replacing characters starting from a specified position. It's effective for adding ellipses or other indicators when a string exceeds a desired length, providing concise summaries or previews.

Example:

<?php
$string = "This is a long sentence that needs to be truncated.";
$maxLength = 20;

if (strlen($string) > $maxLength) {
    $truncatedString = substr_replace($string, '...', $maxLength);
} else {
    $truncatedString = $string;
}

fwrite(STDOUT, $truncatedString . PHP_EOL);
?>

This is a long sente...

Using str_pad() Function

The str_pad() function in PHP pads a string to a certain length with another string. This can be used creatively to ensure that a string does not exceed a certain length by padding it with an empty string and then truncating.

Syntax:

str_pad($input, $pad_length, $pad_string, $pad_type)

Example: This method ensures that the string does not exceed the specified length by padding it and then truncating to the desired length. It is useful for ensuring that a string fits within a certain length constraint while preserving the original content as much as possible.

<?php
$string = "Geeks for geeks is fun";
$desired_length = 10;
$truncated_string = str_pad($string, $desired_length, '');

echo "Original String: " . $string . "<br>";
echo "Modified String: " . substr($truncated_string, 0, $desired_length);
?>

Original String: Geeks for geeks is fun<br>Modified String: Geeks for 

Using str_word_count() Function

The str_word_count() function can be used to count the number of words in a string. Combined with other string manipulation functions, it can help limit a string to a specified number of words.

Example: This example demonstrates how to limit a string to a certain number of words using str_word_count() and explode() functions.

<?php
    $string = "Geeks for geeks is fun and educational";
    echo("Original String : ");
    echo($string . "\n");

    $word_limit = 4; // Desired number of words
    $words = explode(' ', $string); // Split the string into an array of words

    if (count($words) > $word_limit) {
        $new_string = implode(' ', array_slice($words, 0, $word_limit)) . '...';
    } else {
        $new_string = $string;
    }

    echo("Modified String : ");
    echo($new_string . "\n");
?>

Original String : Geeks for geeks is fun and educational
Modified String : Geeks for geeks is...

Using preg_replace() for Truncation

The preg_replace() function allows you to use regular expressions to manipulate strings. You can use it to truncate a string to a specified length by applying a regex pattern that matches the desired number of characters.

Example

<?php
$string = "Geeks for geeks is fun and educational";
echo("Original String : ");
echo($string . "\n");

// Set the maximum length for the string
$max_length = 10;

// Use preg_replace to truncate the string
$new_string = preg_replace('/(.{'.$max_length.'}).*/', '$1...', $string);

echo("Modified String : ");
echo($new_string . "\n");
?>

Using explode() and implode() Functions for Word Limit

The explode() function splits a string by a specified delimiter into an array of words. The implode() function then joins the array elements back into a string. By combining these functions, you can limit a string to a certain number of words.

Example: In this example, we'll limit a string to a specified number of words by first splitting the string into an array of words using explode(), then slicing the array to keep only the desired number of words, and finally joining the array back into a string using implode().

<?php
$string = "Geeks for geeks is a computer science portal for geeks";
$wordLimit = 5;
$wordsArray = explode(" ", $string);
$limitedWordsArray = array_slice($wordsArray, 0, $wordLimit);
$limitedString = implode(" ", $limitedWordsArray);
echo "Original String: $string\n";
echo "Modified String: $limitedString";
?>

Original String: Geeks for geeks is a computer science portal for geeks
Modified String: Geeks for geeks is a