How to use array_merge() and array_combine() in PHP ?
In this article, we will discuss about how to use array_merge() and array_combine() functions in PHP. Both functions are array based functions used to combine two or more arrays using PHP. We will see each function with syntax and implementation
array_merge() Function
This function merges the two or more arrays such that all the arrays have keys and values. The arrays are appended at the end of the first array.
Syntax:
array_merge( array1, array2, ..., array n )
Parameters: Arrays are the input arrays to be merged.
Return type: Single array with merged elements.
Example: PHP example to merge two arrays.
<?php
// Define array1 with keys and values
$array1 = array(
"subject1" => "Python",
"subject2" => "sql"
);
// Define array2 with keys and values
$array2 = array(
"subject3" => "c/c++",
"subject4" => "java"
);
// Merge both array1 and array2
$final = array_merge($array1, $array2);
// Display merged array
print_r($final);
?>
Output
Array
(
[subject1] => Python
[subject2] => sql
[subject3] => c/c++
[subject4] => java
)
Example 2: Merge multiple arrays.
<?php
// Define array1 with keys and values
$array1 = array(
"subject1" => "Python",
"subject2" => "sql"
);
// Define array2 with keys and values
$array2 = array(
"subject3" => "c/c++",
"subject4" => "java"
);
// Define array3 with keys and values
$array3 = array(
"subject5" => "CN",
"subject6" => "OS"
);
// Define array4 with keys and values
$array4 = array(
"subject7" => "data mining",
"subject8" => "C#"
);
// Merge all arrays
$final = array_merge($array1,
$array2, $array3, $array4);
// Display merged array
print_r($final);
?>
Output
Array
(
[subject1] => Python
[subject2] => sql
[subject3] => c/c++
[subject4] => java
[subject5] => CN
[subject6] => OS
[subject7] => data mining
[subject8] => C#
)
array_combine() Function
This function combine only two arrays with one array containing keys and another array containing values.
Syntax:
array_combine(array1, array2)
Parameters:
- array1 is the first array with keys.
- array2 is the second array with values.
Return Value: It returns the combined array.
Example: PHP program to combine arrays.
<?php
// Define array1 with keys
$array1 = array("subject1" ,"subject2");
// Define array2 with values
$array2 = array( "c/c++", "java");
// Combine two arrays
$final = array_combine($array1, $array2);
// Display merged array
print_r($final);
?>
Output
Array
(
[subject1] => c/c++
[subject2] => java
)
Example 2:
<?php
// Define array1 with keys
$array1 = array("subject1",
"subject2", "subject3", "subject4");
// Define array2 with values
$array2 = array( "c/c++", "java", "Python", "HTML");
// Combine two arrays
$final = array_combine($array1, $array2);
// Display merged array
print_r($final);
?>
Output
Array
(
[subject1] => c/c++
[subject2] => java
[subject3] => Python
[subject4] => HTML
)
Difference table of array_merge() and array_combine() in PHP
| Feature/Aspect | array_merge() | array_combine() |
|---|---|---|
| Purpose | Combines two or more arrays into one | Creates an associative array by combining keys and values |
| Input | Accepts multiple arrays | Requires two arrays: one for keys and one for values |
| Key Handling | Overwrites values if keys are duplicated (for associative arrays) | Keys from the first array, values from the second array |
| Output | Returns a single merged array | Returns an associative array |
| Use Case | Merging indexed or associative arrays | Creating an associative array from two separate arrays |