An article introducing PHP to merge arrays and differentiate arrays

In PHP, if two arrays have the same key name, we can use different methods to process them. This article will introduce methods to merge arrays and differentiate arrays.

1. Array Merge

When we have two or more arrays that need to be merged, we can use PHP's built-in array_merge function. This function can combine multiple arrays into one array. For example:

$arr1 = array('a'=>'apple', 'b'=>'banana');
$arr2 = array('c'=>'cat', 'd'=>'dog');
$result = array_merge($arr1, $arr2);
print_r($result);

Output result:

Array
(
    [a] => apple
    [b] => banana
    [c] => cat
    [d] => dog
)

In this example, we use the array_merge function to merge two arrays into one. This function adds the elements of the original array to the new array. If the arrays have the same key name, the later array will overwrite the previous one.

2. Distinguish arrays

In some cases, we want to merge two arrays, but keep the values ​​of the same key names. For this, we can use PHP’s built-in array_replace function. For example:

$arr1 = array('a'=>'apple', 'b'=>'banana');
$arr2 = array('b'=>'bread', 'c'=>'cat');
$result = array_replace($arr1, $arr2);
print_r($result);

Output result:

Array
(
    [a] => apple
    [b] => bread
    [c] => cat
)

In this example, we use the array_replace function to merge two arrays and retain values ​​with different key names. This function overwrites the elements of the original array into the new array. If the arrays have the same key name, the later array will overwrite the previous one.

In addition, we can also use the addition operator " " to merge two arrays, but this method will not retain the values ​​​​of the same key name. For example:

$arr1 = array('a'=>'apple', 'b'=>'banana');
$arr2 = array('b'=>'bread', 'c'=>'cat');
$result = $arr1 + $arr2;
print_r($result);

Output result:

Array
(
    [a] => apple
    [b] => banana
    [c] => cat
)

In this example, we use the addition operator to combine two arrays. This operation adds the elements of the original array to the new array. If the arrays have the same key name, the previous array will overwrite the later one.

Summary

In PHP, we can use different methods to process arrays with the same key name. If we want to merge arrays and keep values ​​with the same keys, we can use array_replace function. If we want to merge two arrays, and if they have the same key name, the latter array will overwrite the previous one, we can use the array_merge function. In addition, we can also use the addition operator " ", but this method will not retain the values ​​of the same key name.

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