How to detect the existence of subarray elements in php two-dimensional array

Detection steps: 1. Use the foreach statement to loop through the outer array elements of the two-dimensional array, the syntax is "foreach($arr as $k=>$v){//loop body}"; 2 . In the loop body, use is_array() to determine whether the outer element "$v" is an array type. If so, use in_array() to determine whether the specified element is in the subarray. The syntax is "if(is_array($v)) {if(in_array(specified element,$v)){//Existence operation}}".

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

In PHP, you can use the foreach statement and is_array () and in_array() functions to detect the existence of subarray elements.

Implementation steps:

Step 1: Use the foreach statement to loop through the outer array elements of the two-dimensional array

foreach($arr as $k => $v){
//循环体代码
}

• Traverse the given $arr array, and in each loop, the value of the current array will be assigned to $v, and the key name will be assigned to $k.

Step 2: In the loop body, use the is_array() function and the in_array() function to determine whether the subarray element exists

• Use the is_array() function to determine whether the outer element is an array type

• If so, use the in_array() function to determine whether the specified element is in the subarray

if(is_array($v)){
		if(in_array(指定元素,$v)){
			echo "指定子数组元素存在";
			break;
		}
}

Implementation code:

<?php
header("content-type:text/html;charset=utf-8");
$arr = array(1,2,3,array(4,5,6),7,8,array(9,10)); 
var_dump($arr);
foreach($arr as $k => $v){
	if(is_array($v)){
		if(in_array("9",$v)){
			echo "指定子数组元素存在";
			break;
		}
		
	}
}
?>

##If this element does not exist, there will be no prompt. Improve it:

<?php
header("content-type:text/html;charset=utf-8");
function f($arr,$s){
	$c=0;
	foreach($arr as $k => $v){
		if(is_array($v)){
			if(in_array($s,$v)){
				$c=1;
				break;
			}
		}
	}
	if($c==1){
		echo "指定子数组元素 $s 存在<br>";
	}else{
		echo "指定子数组元素 $s 不存在<br>";
	}
}


$arr = array(1,2,3,array(4,5,6),7,8,array(9,10)); 
var_dump($arr);
f($arr,9);
f($arr,11);
?>

Description:

in_array() function searches whether the specified value exists in the array. Syntax format:

in_array ( $search , $array ,$strict)

##Parametersearcharraystrict Return value: TRUE if the value is found in the array, FALSE otherwise.

Description
Required. Specifies the value to search for in the array.
Required. Specifies the array to search.
Optional. If this parameter is set to TRUE, the in_array() function checks whether the data being searched is of the same type as the value of the array.

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