(go) JS function parameter Set default value

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 30

But JS can not be so defined, if you writefunction Simue (a=1,b=2) {} will prompt for missing objects.

There is an array of stored parameters in the JS functionarguments , 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 30