How to use if statement in php to determine whether a value is in an array

Implementation steps: 1. Use the foreach statement to loop through the array, the syntax is "foreach ($array as $value){//Loop body statement block;}"; 2. In the loop body, use the if statement to match The "===" operator can be used to determine whether the specified value is in the array. The syntax "if($value==="specified value"){echo "The specified value $z is in the array
";break; }".

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

In PHP, you can use the if statement with foreach statement and the "===" operator to determine whether the specified value is in the array.

Implementation steps:

Step 1: Use the foreach statement to loop through the array

foreach ($array as $value){
    //循环体语句块;
}

Traverse the given $array array , the value of the current array will be assigned to $value in each loop.

Step 2: In the loop body, use the if statement with the "===" operator to determine whether the specified value is in the array

if($value==="指定值"){
echo "指定值 $z 在数组中<br>";
break;
}

Complete Sample code:

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
function f($arr,$z){
	foreach($arr as $v){
		if($v===$z){
			echo "指定值 $z 在数组中<br>";
			break;
		}
//		else{
//			echo "指定值 $z 不在数组中<br>";
//		}
	}
}
$arr=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
echo "原数组：";
var_dump($arr);
f($arr,"green");
?>

Cannot be executed, not in the array. So modify it and add an intermediate variable to record the status

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
function f($arr,$z){
	$c=0;
	foreach($arr as $v){
		if($v===$z){
			$c=1;
			break;
		}
		else{
			$c=0;
		}
	}
	if($c==1){
		echo "指定值 $z 在数组中<br>";
	}
	else{
		echo "指定值 $z 不在数组中<br>";
	}
}

$arr=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
echo "原数组：";
var_dump($arr);
f($arr,"green");
f($arr,"b");
?>

Recommended study: "PHP Video Tutorial"

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