How to Find the Foreach Index in PHP

  1. Use the key Variable to Find the Foreach Index in PHP
  2. Use index Variable to Find the Foreach Index in PHP
  3. Use Both key and index Variable to Find the Foreach Index in PHP

In this article, we will introduce methods to find the foreach index.

  • Using the key variable
  • Using the index variable
  • Using both the key and index variable

Use the key Variable to Find the Foreach Index in PHP

The variable key stores the index of each value in foreach loop. The foreach loop in PHP is used as follows.

foreach($arrayName as $value){
    //code
}

The variable value stores the value of each element of the array.

<?php 
$array = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10); 

foreach ($array as $key => $value) { 
    echo "The index is = " . $key . ", and value is = ". $value; 
    echo "\n";
}   
?>

The key variable here contains the index of foreach loop. The variable value shows the value of each element in the array.

Output:

The index is = 0, and the value is = 1
The index is = 1, and the value is = 2
The index is = 2, and the value is = 3
The index is = 3, and the value is = 4
The index is = 4, and the value is = 5
The index is = 5, and the value is = 6
The index is = 6, and the value is = 7
The index is = 7, and the value is = 8
The index is = 8, and the value is = 9
The index is = 9, and the value is = 10

Use index Variable to Find the Foreach Index in PHP

The variable index is used as an additional variable to show the index of foreach in each iteration.

<?php 
// Declare an array 
$arr = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10); 
$index = 0;

foreach($arr as $key=>$val) {
    echo "The index is $index";
    $index++;
    echo "\n";
}
?>
Warning

The index variable is first initialized with a value. It is then incremented each time the loop iterates.

Output:

The index is 0
The index is 1
The index is 2
The index is 3
The index is 4
The index is 5
The index is 6
The index is 7
The index is 8
The index is 9

Use Both key and index Variable to Find the Foreach Index in PHP

Now, we will use both the key variable and an additional variable index to find the index of foreach.

<?php 
  
// Declare an array 
$arr = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10); 
$index = 0;

foreach ($arr as $key=>$value) {    
    echo "The index is $index";
    $index = $key+1;
    echo "\n";
}
  
?>

We have stored the value of the key variable with an increment in its value in the index variable. In this way, we can find the index of foreach using both the key variable and index variable.

Output:

The index is 0
The index is 1
The index is 2
The index is 3
The index is 4
The index is 5
The index is 6
The index is 7
The index is 8
The index is 9