What is function overloading in JavaScript?

JavaScript does not support Function Overloading. The following shows function overloading −

function funcONE(x,y) {
   return x*y;
}
function funcONE(z) {
   return z;
}

The above will not show an error, but you won't get desired results. On calling,

// prints 5
funcONE(5);

// prints 5, not 30
funcONE(5,6);

JavaScript does not support function overloading natively. If we will add functions with the same name and different arguments, it considers the last defined function.