Smallest function argument validation

smallest-validation.js

//smallest function argument validation + throwing an error if wrong type

//is string
var a = "";
a.charAt(0); //OK
a = 1;
a.charAt(0); //TypeError: Object 1 has no method 'charAt'

//is number
var a = 1;
a.toFixed() //OK
a = ""
a.toFixed() //TypeError: Object has no method 'toFixed'

//is function
var a = function(){};
a.call||undefined.f //OK
a = "";
a.call||undefined.f //TypeError: Cannot read property 'f' of undefined

//is array
var a = [];
a.pop||undefined.a //OK
a = 1;
a.pop||undefined.a //TypeError: Cannot read property 'a' of undefined

//not null or undefined
var a = 0;
a!=null||undefined.n //OK
a = null;
a!=null||undefined.n //TypeError: Cannot read property 'n' of undefined