What is the difference between call and apply? What is the difference between using call and apply to invoke a function? var func = function(){ alert('hello!'); }; func.apply(); vs func.call(); Are there performance differences between the two methods? When is it best to use call over apply and vice versa? Solution: The difference is that apply lets you invoke the function with arguments as an array; call requires the parameters be listed explicitly. A useful mnemonic is "A for array and C for comma." See MDN's documentation on apply and call. Pseudo