Php array add and delete element program code

Added the data element functions, including array_push () and array_unshift ().

1. Add elements at the end of the array

1. array_push

Usage

The code is as follows:	Copy code
<? Php $ Stack = array ("orange", "banana "); Array_push ($ stack, "apple", "raspberry "); Print_r ($ stack ); ?> Output: Array ( [0] => orange [1] => banana [2] => apple [3] => raspberry ) 2. $ arr [] Usage <? Php $ Arr = array ("orange", "banana "); $ Arr [] = 'apple '; Print_r ($ arr ); ?>

The two effects are the same.

Note: If array_push () is used to add a unit to the array, it is better to use $ array [] =, because there is no additional burden to call the function.

2. Insert elements at the beginning of the array

1. array_unshift

Usage

The code is as follows:	Copy code
<? Php $ Queue = array ("orange", "banana "); Array_unshift ($ queue, "apple", "raspberry "); Print_r ($ queue ); ?> Output Array ( [0] => apple [1] => raspberry [2] => orange [3] => banana )

Delete the array element unset, or directly set null

If you want to delete an element from an array, you can use the unset directly, but what you see today surprised me.

The code is as follows:	Copy code
<? Php $ Arr = array ('A', 'B', 'C', 'D '); Unset ($ arr [1]); Print_r ($ arr ); ?>   Print_r ($ arr)

The result is not that. The final result is Array ([0] => a [2] => c [3] => d)

 

So how can we fill in the missing elements and re-index the array? The answer is array_splice ():

The code is as follows:	Copy code
<? Php $ Arr = array ('A', 'B', 'C', 'D '); Array_splice ($ arr, 1, 1 ); Print_r ($ arr ); ?> After print_r ($ arr), the result is Array ([0] => a [1] => c [2] => d)

Deletes the specified element of an array.

For example, the array_slice () function extracts a value from the array based on the conditions and returns the result.

Array_slice (array, offset, length, preserve)

Array: array

Offset: specifies the start position of the retrieved element. If it is a positive number, it is taken from the beginning to the end. If it is a negative value, it is taken from the back to the absolute value of the offset.

 

The code is as follows:	Copy code
<? Php $ A = array (0 => "Dog", 1 => "Cat", 2 => "Horse", 3 => "Bird "); Print_r (array_slice ($ a, 1, 2 )); ?> Output Array ([0] => Cat [1] => Horse)

The array_shift () function also deletes the first element in the array and returns the value of the deleted element.

The relative array_pop () function deletes the last element in the array.

I think array_search () is more practical when using several functions.

The array_search () function is the same as the in_array () function. You can find a key value in the array. If this value is found, the key name of the matching element is returned. If not found, false is returned.

The code is as follows:	Copy code
$ Array = array ('1', '2', '3', '4', '5 '); $ Del_value = 3; Unset ($ array [array_search ($ del_value, $ array)]); // use unset to delete this element Print_r ($ array ); Output Array ('1', '2', '4', '5 ');