Default Arguments
It allows to set default values for function Arguments, if no value or if undefined is passed.
Example what happen when no parameter is passed to a function-
function addTest(x,y)
{
return x + y;
}
addTest()
Output:-
NaN
Example:-
function test(x, y = 1)
{
return x * y;
}
console.log(test(10, 2));
console.log(test(5));
Output:-
20
5
Now Example to pass arguments to function using ES6:-
function Add(x, y)
{
y = (typeof y !== 'undefined') ? y : 1
return x * y
}
Add(5, 2)
Add(5)
Output:-
5