Function.apply (obj, args) method to receive two parameters
obj: Function will replace this object this object class
args: This is an array, it will be passed as a parameter Function (args -> arguments)
var oldParseInt = parseInt; console.log(oldParseInt("10")); var count = 0; window.parseInt = function(){ count+=1; // return oldParseInt(arguments[0]); return oldParseInt.apply(null,arguments[0]); }
Because the second argument did not pass an array, it reported this error.
Correct wording is:
var oldParseInt = parseInt; console.log(oldParseInt("10")); var count = 0; window.parseInt = function(){ count+=1; // return oldParseInt(arguments[0]); return oldParseInt.apply(null,arguments); }