Check foreach Loop Key Value in PHP

This article will introduce a method to check the foreach loop key value in PHP.

Use the foreach Loop to Check the foreach Loop Key Value in PHP

We can use a foreach loop to check the foreach loop key value. The foreach loop traverses through an array whose keys and elements can be accessed in the loop. The correct syntax to use this loop is as follows.

foreach($arrayName as $variableName){
    //PHP code
}

If we have an associative array, we can use this loop in the following way:

foreach($arrayName as $key => $variableName){
    //PHP code
}

The detail of its parameters is as follows:

Variable Detail
$arrayName mandatory This is the array we want to traverse.
$variableName mandatory It is the variable name for array elements.
$key optional It is the variable name for keys of the array.

The foreach loop stops when it traverses the whole array.

We can use the echo() function to display the array keys.

The program below shows how we can use foreach loop to check foreach loop key value in PHP.

<?php 
$result = array("firstname"=>"Olivia", "lastname"=>"Mason", "marks"=>85, "attendance"=>100);
echo("The value of keys of the array are:\n");
foreach ($result as $key => $value)
{
    echo($key);
    echo("\n");
}
?> 

We have looped through the array and displayed its keys.

Output:

The value of keys of the array are:
firstname
lastname
marks
attendance