Introduction to higher-order functions in JavaScript

Higher order functions: higher order looks like an esoteric term for advanced programming techniques, which I think I did when I first saw it.

Higher-order functions of JavaScript

However, a higher-order function is simply a function that takes a function as a parameter or return value . Take the following hello,world as a simple example.

var Moqi = function (p1) {    this. Add = function (p2) {        return' + p2;    };     return add;}; // We can use this function Console.log (Moqi ('Hello') (' World  '));

Maybe the process is a bit confusing, just look at the details.

typeof Moqi ('hello')//"function"Moqi ('Hello ' )//function (p2) {//    return p1 + "+ p2; // }

In other words, Moqi (' Hello ') is a function, Moqi (' Hello ')

var m = Moqi ('Hello')       m ('World')  //"Hello,world"

From the above, higher-order functions can make the code more concise and efficient. Naturally, we can also create a function like this:

varMoqi =function (p1) {returnfunction (p2) {returnfunction (p3) {returnP1 +','+ P2 +' '+P3; }    };}; Moqi ('Hello')(' World')('Phodal')//"Hello,world phodal"

Restore higher-order functions

Increasingly complex, the need to introduce higher-order function abstractions is the occurrence of repetitive or similar code. We then revert to the previous function:

var Moqi = function (p1) {     this. Add =  function (p2) {        return  function ( P3) {            return', ' ' +p3;        }    };     return  This . Add;};

And then create a new function.

 var  moqi =        Function (p1) { this . Add = function (p2) {  this . Add1 = function (p3) { 
    
     return 
     p1 +  " ,   " + P2 + "          '  +

Using the call method in JavaScript, you will have:

varMoqi =function (p1) {varSelf = This; function fd (p2) { This. Add1 =function (p3) {returnP1 +','+ P2 +' '+P3;    }; } Self.add=function (p2) {Fd.call ( This, p2); return  This. Add1;    }; returnSelf.add;};

Examples of higher order functions

Add = function (b) {    return a + b;}; function Math (func,array) {    return func (array[0],array[1]);} Console.log (Math (add,[1,2])); // Math (add,[1,2]) // 3

Introduction to higher-order functions in JavaScript