PHP debugging encounters Invalid argument supplied for foreach()

1. Preparation before use:

Basic syntax of is_array():

bool is_array ( mixed $var )

The is_array() function is used to detect whether a variable is aArray.

• $var: Variable to be detected

• If the variable being detected is an array, return TRUE, otherwise return FALSE.

Usage demonstration:

<?php
    $arr_site = array(&#39;PHP&#39;, &#39;JAVA&#39;, &#39;C#&#39;);
    if(is_array($arr_site)){
        echo &#39;变量 $arr_site 是一个数组&#39;;
    } else {
        echo &#39;变量 $arr_site 不是一个数组&#39;;
    }
?>

The output result is: the variable $arr_site is an array.

2. Error reason:

When using foreach in php to loop through times Invalid argument supplied for foreach() The error is because the looped data is not a valid array. We can use is_array() to determine the data source before foreach.

if(is_array($data))
{
    foreach($data as $value)
    {...}
}

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