我对 PHP in_array() function 做错了什么，它没有返回所需的值

Question

I'm having a problem with PHP in_array() method, it is quite simple but not working as it should. I've tried many solutions from the internet. But everything seems okay. Can you please help me find a mistake in my syntax or logic

Here is my code

$array1 = array('1','0.2','1.3','0.6','1.4','1.6','12','1.2','11.2');
$array2 = [];
for($i=0.1; $i<=15;){
    $array2[] = $i;
    $i+= 0.1;
}

foreach($array2 as $key=>$value){
    // print_r($array1);
    if(in_array($value, $array1)){
        echo $value. ' OK <br>';
    }else{
        echo $value. '<br>';
    }
    
}

Here is my output image

Red Highlighted text is returned true and green is not returning

Answer 1

You need to either use numbers or strings but not compare numbers to strings and hope that they will be the same. An easy fix would be to use strval to convert the generated number to a string in the comparison test

<?php

    $array1 = array('1','0.2','1.3','0.6','1.4','1.6','12','1.2','11.2');

    $array2 = [];
    for($i=0.1; $i<=15; $i+= 0.1 )$array2[] = $i;


    foreach($array2 as $key=>$value){

        if( in_array( strval($value),  $array1 )){
            echo $value. ' OK <br>';
        }else{
            echo $value. '<br>';
        }
        
    }

?>

Answer 2

You must compare a string array with a string, add a conversion before comparing or while you're initializing your second array.

This will solve your issue:

$array1 = array('1','0.2','1.3','0.6','1.4','1.6','12','1.2','11.2');
$array2 = [];
$i = 0.1;
while( $i <= 15 ) :
    $array2[] = strval( $i );
    $i = $i + 0.1;
endwhile;

foreach($array2 as $value){
    // print_r($array1);
    if(in_array($value, $array1)){
        echo $value. ' OK <br>';
    }else{
        echo $value. '<br>';
    }
    
}