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In this article Xiaobian for you to introduce in detail "what are the methods of traversing arrays in php", the content is detailed, the steps are clear, and the details are handled properly. I hope that this article "which methods of traversing arrays in php" can help you solve your doubts.

There are five traversal methods: 1, with "for ($item0); 3, with" while (list ($kjagio v) = each (array)) "; 4, with" array_map (callback function, array) "and so on.

Operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

Five methods of traversing arrays in php

Method 1: use for loop statement

The for loop pre-defines the variables that control the number of loops in the for statement, so the for loop statement can loop according to the known number of loops, which is suitable for situations where you know exactly how many times the script needs to run.

The syntax format of the for loop is as follows:

For (initialization statement; loop condition; variable update-self-increasing or self-decreasing) {statement block;}

Let's take a look at the code example:

Output result:

Method 2: use foreach loop statement

Foreach is a statement specially designed to traverse an array. It is a common method when traversing an array and provides great convenience in traversing an array. After PHP5, you can also traverse objects (foreach can only be applied to arrays and objects).

The foreach statement traverses an array independent of the array subscript and can be used for discontiguous indexed arrays and associative arrays with strings as subscript.

Let's take a look at the code example:

Output result:

Iterate through the given $array array, assigning the value of the current array to $value and the key name to $key in each loop.

Method 3: use while loop + each () + list ()

The each () function returns the current key value in the array and moves the array pointer forward. After each () is executed, the array pointer stays at the next element in the array or at the end of the array.

The list () function is used to assign values to a set of variables in a single operation.

The while loop + each () function + list () function can traverse the array. Let's take a look at the code example:

Output result:

Method 4: use the array_map () function

Use anonymous functions to process each element in the array. Return a new array after traversal

You can process multiple arrays at the same time.

Method 5: use the array_walk () function

Iterate through your array in the form of reference passing, with no return value, and only one array can be processed.

Have you noticed & $item? yes, there is an extra &, which means that your parameter is passing and receiving data by reference. All you have to do is find a way to change this parameter.

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