The default value problem for JS's function parameter

PHP has a handy use when defining a function to set a default value directly to the parameter, such as:

function simue ($a =1, $b =2) {
return $a + $b;
}
Echo Simue (); Output 3
Echo Simue (10); Output 12
echo Simue (10,20); Output

But JS can not be so defined, if write function Simue (a=1,b=2) {} will prompt the missing object.

The JS function has an array of stored parameters arguments , and the parameters obtained by all functions are saved to the array by the compiler. So our JS version of the support parameter default value of the function can be implemented in another way, modify the above example:

function  Simue (){
var a = Arguments[0]? Arguments[0]: 1;
var B = arguments[1]? ARGUMENTS[1]: 2;
return a+b;
}
Alert (Simue ()); Output 3
Alert (Simue (10)); Output 12
Alert (Simue (10,20)); Output

The default value problem for JS's function parameter