Mastering TypeScript 3 - Third Edition

Anonymous functions

The JavaScript language also has the concept of anonymous functions. These are functions that are defined on the fly and don't specify a function name. Consider the following JavaScript code:

var addVar = function(a,b) { 
    return a + b; 
} 
 
var addVarResult = addVar(2,3); 
console.log("addVarResult:"" + addVarResult);

Here, we define a function that has no name and adds two values. Because the function does not have a name, it is known as an anonymous function. This anonymous function is then assigned to a variable named addVar. The addVar variable can then be invoked as a function with two parameters, and the return value will be the result of executing the anonymous function. The output of this code will be as follows: