call() method in JavaScript

gistfile1.txt

The call() Method
The first function method for manipulating this is call(), which executes
the function with a particular this value and with specific parameters.
The first parameter of call() is the value to which this should be equal
when the function is executed. All subsequent parameters are the parameters that should be passed into the function. For example, suppose you
update sayNameForAll() to take a parameter:

function sayNameForAll(label) {
 console.log(label + ":" + this.name);
}
var person1 = {
 name: "Nicholas"
};
var person2 = {
 name: "Greg"
};
var name = "Michael";
sayNameForAll.call(this, "global"); // outputs "global:Michael"
sayNameForAll.call(person1, "person1"); // outputs "person1:Nicholas"
sayNameForAll.call(person2, "person2"); // outputs "person2:Greg"