Can comparing the result of isset() function to a specific value lead to unexpected results in PHP?

Yes, comparing the result of isset() function directly to a specific value can lead to unexpected results because isset() returns a boolean true if a variable is set and not null, regardless of its actual value. To properly compare the value of a variable, you should use additional checks such as === for strict comparison. 

// Incorrect comparison using isset()
$var = 0;
if(isset($var) == 0){
    echo "Unexpected result";
}

// Correct comparison using additional checks
$var = 0;
if(isset($var) && $var === 0){
    echo "Expected result";
}

Keywords

isset comparison unexpected results PHP

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