PHP array merging, appending and connecting methods (array_merge(), array_combine() functions)

1. First, merge the arrays.

array_merge() function merges arrays together and returns a combined array. The resulting array starts with the first input array parameter, and is added sequentially in the order in which subsequent array parameters appear. Its form is: array array_merge (array array1 array2…,arrayN) The elements of one or more arrays can be combined, with the values in one array appended to the previous array. Returns the resulting array.

If the input array has the same string key name, the value after the key name will overwrite the previous value. However, if the array contains numeric keys, the subsequent values will not overwrite the original values, but will be appended to them.

If only an array is given and the array is numerically indexed, the key names are re-indexed in a consecutive manner.

Example:

Output result: Array ( [0] => A [1] => 4 [2] => 9 [3] => 3 [4] => K [5] => 7 [6] => 5 [7] => Q [8] => 6 [9] => 8 [10] => 2 [11] => J )

2, append array recursively The array_merge_recursive() function is the same as array_merge() and can merge two or more arrays together to form a combined array. The difference between the two is that the function will handle it differently when a key in an input array already exists in the result array. array_merge() will overwrite the previously existing key/value pairs and replace them with the current input array The key/value pair in the array_merge_recursive() will merge the two values together to form a new array, and use the original key as the array name. There is also a form of array merging, which is to recursively append arrays.

The form is: array array_merge_recursive(array key,array values)

Example:

 100, "James" => 85); $class2 = array("Micky" => 78, "John" => 45); $classScores = array_merge_recursive($class1, $class2); print_r($classScores); ?>

Output result: Array ( [John] => Array ( [0] => 100 [1] => 45 ) [James] => 85 [Micky] => 78 )

3, concatenate two arrays The array_combine() function will get a new array, which consists of a set of submitted keys and corresponding values. Its form is: array array_merge(array array1,array array2[…,array arrayN])

Note that the two input arrays must be the same size and cannot be empty.

Example:

Output result: Array ( [AL] => Alabama [AK] => Alaska [AZ] => Arizona [AR] => Arkansas )

This is the introduction to the methods and examples of merging, appending and connecting arrays in PHP. I hope it can help everyone.

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