How to determine if arrays have the same elements in php

Judgment steps: 1. Use array_unique() to remove duplicate values ​​in the array. The syntax "array_unique (original array)" will return a deduplicated array; 2. Use count() to obtain the original array and the deduplicated array respectively. Repeat the array length of the array and determine whether the lengths of the two arrays are equal. The syntax is "count (original array) == count (deduced array)". If the lengths of the two arrays are equal, there are no identical elements in the arrays. Otherwise, there are no identical elements in the arrays. There are the same elements.

The operating environment of this tutorial: Windows 7 system, PHP version 8.1, DELL G3 computer

php determines whether the arrays have the same elements, that is Determine whether array elements have duplicate values.

In php, you can use the array_unique() and count() functions to make judgments.

Judgment steps:

Step 1: Use the array_unique() function to remove duplicate values ​​in the array

array_unique(array,sortingtype)

Parameters	Description
array	Required. Specifies an array.
sortingtype	Optional. Specifies the sorting type. Possible values: SORT_STRING - Default. Treat each item as a string. SORT_REGULAR - Sort each item in regular order (Standard ASCII, does not change type). SORT_NUMERIC - Treat each item as a number. SORT_LOCALE_STRING - Treat each item as a string, based on the current locale (can be changed via setlocale()).

Return value: Returns the filtered deduplication array.

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$arr=array(3,4,2,3,6,4,7,2,8,9,1);
var_dump($arr);
$res=array_unique($arr);
echo "去重后的数组：";
var_dump($res);
?>

Step 2: Use the count() function to obtain the length of the original array and the deduplicated array, and determine whether the lengths of the two arrays are equal

The count() function can count the number of all elements in the array, that is, obtain the length of the array.

• If the lengths of the two arrays are equal, there are no duplicate values ​​in the arrays

• If the lengths of the two arrays are not equal, it means that there are elements that are Removed, that is, there are duplicate values ​​in the array.

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
$arr=array(3,4,2,3,6,4,7,2,8,9,1);
var_dump($arr);
$res=array_unique($arr);
echo "去重后的数组：";
var_dump($res);

$len1=count($arr);
$len2=count($res);
echo "原数组的长度为： $len1 <br>";
echo "去重数组的长度为： $len2 <br><br>";

if($len1==$len2){
	echo "两数组长度相等，数组里有没有相同的元素";
}else{
	echo "两数组长度不相等，数组里有相同的元素";
}
?>

Explanation:

count() function can count all elements in the array The number, or the number of attributes in the object, the syntax format is as follows:

count($array , $mode )

The parameter description is as follows:

• $array: is the array or object to be counted;
• $mode: is an optional parameter and can be omitted.
  • If the $mode parameter is omitted, or set to COUNT_NORMAL or 0, the count() function will not detect multidimensional arrays;
  • If $mode is set to COUNT_RECURSIVE or 1, the count() function Will recursively count the number of elements in the array, especially useful for counting the number of elements in multi-dimensional arrays.

Tip: If $array is neither an array nor an object, the count() function will return 1; if $array is equal to NULL, the count() function Return 0.

sizeof() function is an alias of count() function, that is, the function and usage of sizeof() function are exactly the same as count() function.

Recommended learning: "PHP Video Tutorial"

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