Check if String Contains Backslash in PHP

This tutorial will discuss multiple ways to check if string contains backslash in PHP.

Table Of Contents

Method 1: Using strpos() function

To check if a string contains a backslash i.e. we can use the strpos() function in PHP. We pass the string as the first argument and as the second argument.

If strpos() returns false, it means that the string does not contain a backslash. Otherwise, it will return the position of the first occurrence of backslash i.e. in the string.

We have created a separate function,

function hasBackslash($strValue)
{
    return strpos($strValue, '\') !== false;
}

It accepts a string as an argument and returns true if the string contains a backslash.

Let’s see the complete example,

<?php
/**
 * Check if a string contains a backslash.
 *
 * @param string $strValue The string to validate.
 * @return bool True if the string contains a backslash,
 *              False otherwise.
 */
function hasBackslash($strValue)
{
    return strpos($strValue, '\') !== false;
}

$strValue = 'This string contains a backslash \ somehere';

// Check if String contains Backslash
if (hasBackslash($strValue)) {
    echo "The string contains a backslash.";
} else {
    echo "The string does not contain a backslash.";
}
?>

Output

The string contains a backslash.

Method 2: Using preg_match() function

We can also use regular expressions to check if a string contains a backslash.

The regex pattern we can use is ‘/\\/’. By using the preg_match() function and passing the regex pattern and the string as arguments, we can determine if the string contains a backslash. If preg_match() returns 1, it means that the string contains a backslash.

Let’s see the complete example,

<?php
/**
 * Check if a string contains a backslash.
 *
 * @param string $strValue The string to validate.
 * @return bool True if the string contains a backslash,
 *              False otherwise.
 */
function containsBackslash($strValue)
{
    return preg_match('/\\/', $strValue) === 1;
}

$strValue = 'This string contains a backslash \ somehere';

// Check if String contains Backslash
if (containsBackslash($strValue)) {
    echo "The string contains a backslash.";
} else {
    echo "The string does not contain a backslash.";
}
?>

Output

The string contains a backslash.

Summary

Today, we learned about multiple ways to check if string contains backslash in PHP.