How to find the Indices of All Occurrences of Substring in PHP - Step by Step Examples

How to find the Indices of All Occurrences of Substring in PHP ?

Answer

To find the indices of all occurrences of a substring in PHP, you can use the strpos function in a loop to find all occurrences and store their indices in an array.


✐ Examples

1 Find Indices of All Occurrences in String

In this example,

  1. We create a string variable $str with a string value.
  2. We use a loop with the strpos function to find all occurrences of a specific substring within $str and store their indices in an array.
  3. Finally, we print the array of indices.

PHP Program

<?php
$str = 'Hello Hello Hello';
$substr = 'Hello';
$indices = [];
$index = strpos($str, $substr);
while ($index !== false) {
    $indices[] = $index;
    $index = strpos($str, $substr, $index + 1);
}
echo 'Indices of all occurrences: ';
print_r($indices);
?>

Output

Indices of all occurrences: Array
(
    [0] => 0
    [1] => 6
    [2] => 12
)

2 Find Indices of All Occurrences in Another String

In this example,

  1. We create two string variables $str1 and $str2 with different values.
  2. We use a loop with the strpos function to find all occurrences of $str2 within $str1 and store their indices in an array.
  3. Finally, we print the array of indices.

PHP Program

<?php
$str1 = 'apple banana cherry banana';
$str2 = 'banana';
$indices = [];
$index = strpos($str1, $str2);
while ($index !== false) {
    $indices[] = $index;
    $index = strpos($str1, $str2, $index + 1);
}
echo 'Indices of all occurrences: ';
print_r($indices);
?>

Output

Indices of all occurrences: Array
(
    [0] => 6
    [1] => 20
)

Summary

In this tutorial, we learned How to find the Indices of All Occurrences of Substring in PHP language with well detailed examples.


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