Php array (2)-php Tutorial

Php array (2) add elements to the array header

Array_unshift ($ states, 'AAA'); add aaa to the header of the array $ states, that is, the first

Add elements at the end of the array

Array_push ($ states, 'AAA'); add aaa to the end of the array $ states, that is, the last

Delete element from array header

Array_shift ($ states); deletes the first element of the array $ states

Deletes an element from the end of an array.

Array_pop ($ states); delete the last element of the array $ states

Returns true and false when searching for a specific value of an array.

In_array ($ states, 'AAA'); searches for the $ states array to check whether the value aaa exists. if the value aaa exists, true is returned.

Returns true and false when searching for the key of the associated array.

Array_key_exists ('AAA', $ states) returns true if the key in the array $ states contains an aaa key.

Search for the value of the associated array

Array_search ('AAA', $ states) returns true if the value of $ states in the array contains the value aaa. this is a bit like in_array, but this is dedicated to searching associated arrays, the latter is to search all arrays, including normal arrays

Obtain the array key

$ Keys = array_keys ($ states); the keys of all the arrays are returned and arranged as normal arrays, such as Array ([0] => aaa, [1] => bbb)

Get array value

$ Values = array_values ($ states); similar to the above.

Get the current array key

$ Test = array ('AAA' => 'we', 'BBB '=> 'you'); while ($ key = key ($ test )) {// The key () is the key used to obtain the current array. The key is queried sequentially from 0. Therefore, the first key is aaa, and the second key is bbb echo $ key; next ($ test); // because the key does not move the array pointer and points to a key, it does not change. Therefore, you need to use the next method to move to the next pointer}

Get the current array value

Similar to the above, but the key is changed to current

Obtains the keys and values of the current array.

Similar to the above, use each

Move an array pointer

There are "next", "prev", "reset", and "end", which are respectively the next, first, first, and last.

Refer to the previous next example.

Determine the array size

count($garden);

Count the frequency of array keys

Array_count_values ($ states); return value: Array ([aaa] => 2, [bbb] => 1)

Determine unique array elements

Deletes all repeated values in the array and returns an array consisting of unique values.

array_unique($states);