PHP deletes the specified element in an array based on key implementation method

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The elements in the PHP array exist in a key-value pair (' key ' = ' value '), and sometimes we need to delete an element specified in the array based on the key.

  function Bykey_reitem ($arr, $key) {     if (!array_key_exists ($key, $arr)) {       return $arr;     }     $keys = Array_keys ($arr);     $index = Array_search ($key, $keys);     if ($index!== FALSE) {       array_splice ($arr, $index, 1);     }     return $arr;   }   $data = Array (' name ' = ' apple ', ' age ' =>12, ' address ' = ' Chinaguangzhou ');   $result = Array_remove ($data, ' name ');   Var_dump ($result);

Instructions for using the function:

1, Array_search ()

Definition and usage

The Array_search () function, like In_array (), looks for a key value in the array. If the value is found, the key name of the matching element is returned. Returns False if it is not found.

Before PHP 4.2.0, the function returned null instead of false on failure.

If the third parameter, strict, is specified as true, the key name of the corresponding element is returned only if the data type and value are consistent.

Grammar

Array_search (value,array,strict)
Parameter description
Value is required. Specifies the value to search for in the array.
Array required. The array to be searched.
Strict is optional. Possible values:
True
False-Default

If the value is set to True, the type of the given value is also checked in the array

Example 1

  <?php    $a =array ("a" = "Dog", "b" = "Cat", "C" and "Horse");    Echo Array_search ("Dog", $a);  ? >

2, Array_splice ()

Definition and usage

The Array_splice () function, like the Array_slice () function, selects a series of elements in an array, but does not return, but instead deletes them and replaces them with other values.

If the fourth argument is supplied, the previously selected elements will be replaced by the array specified by the fourth parameter. The last generated array will be returned.

Grammar

Array_splice (Array,offset,length,array)

Parameter description

array required. Specifies the array.

offset required. Numerical. If offset is positive, the offset specified by the value in the input array begins to be removed. If offset is negative, it is removed from the offset specified by the value of the countdown at the end of the input array.

length is optional. Numerical. If this argument is omitted, all parts of the array from offset to end are moved. If length is specified and positive, then so many elements are removed. If length is specified with a negative value, all elements in the middle of offset to the end of the array ending with length are removed.

the element to which the array is removed is substituted by the elements in this array. If no value is removed, the elements in this array are inserted into the specified position.

Hints and Notes

Tip: If the function does not delete any elements (length=0), the alternate array is inserted from the position of the start parameter. (see example 3)

Note: The keys in the alternate array are not preserved.

Instance

<?php     $a 1=array (0=> "Dog",1=> "Cat",2=> "Horse",3=> "Bird");     $a 2=array (0=> "Tiger",1=> "Lion");     Array_splice ($a 1,0,2, $a 2);     Print_r ($a 1);     Output:    array ([0] = Tiger [1] = Lion [2] = = Horse [3] = Bird)?>    //Same as Example 1, but output returns an array of: <?php
   $a 1=array (0=> "Dog",1=> "Cat",2=> "Horse",3=> "Bird");     $a 2=array (0=> "Tiger",1=> "Lion");     Print_r (Array_splice ($a 1,0,2, $a 2));? >    //output:    Array ([0] = Dog [1] = Cat    )//length parameter set to 0:<?php     $a 1=array (0=> "Dog", 1=& gt; " Cat ");     $a 2=array (0=> "Tiger",1=> "Lion");     Array_splice ($a 1,1,0, $a 2);     Print_r ($a 1);? >   //output:   Array ([0] = Dog [1] = Tiger [2] = Lion [3] = Cat)

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