js can use Function to create functions
var func=new Function();
This object can convert strings to functions
var func=new Function("console.write('hello world')");
func();
There is a built-in arguments variable in the function, according to which all the parameters passed by the function can be obtained; this allows us to use functions with variable parameter lists;
function test(){
for(var i=0;i<arguments.length;i++){
console.write(argument[i]);
}
}
test(1,2,3,4);
How to use the instanceof keyword; determine whether the constructor exists on the prototype chain of the object;
function Person(){};
var p = new Person ();
console.write(p instanceof Person);//true;
console.write(p instanceof Object);//true;