Optional parameter $yyy precedes required parameter $xxx

Question

Deprecated:Requiredparameter$xxxfollowsoptionalparameter$yyyin...Since upgrading to PHP8.0, this error will be thrown when running the following code: functiontest_function(int$var1=2,int$var2){return$var1/$var2;}this There was no problem in past versions of PHP.

P粉021553460 · Answer

Required parameters without default values should come first.

function test_function(int $xxx, int $yyy = 2)
{
    return $xxx * $yyy;
}

P粉427877676 · Answer

This method of function declaration has been deprecated in PHP 8.0. It never makes sense to write a function like this because all arguments (until the last required one) need to be specified when calling the function. It's also using the Causing confusion ::getNumberOfRequiredParameters" rel="noreferrer">ReflectionFunctionAbstract class to parse functions and methods.

The new deprecation simply ensures that function signatures follow the common-sense assumption that required parameters that must be present should always be declared before optional parameters.

This function should be rewritten to remove the default values for earlier parameters. Since the function can never be called without declaring all arguments, this should have no effect on its functionality.

function test_function(int $var1, int $var2) {
    return $var1 / $var2;
}