JS--function

<title>js– function</title> js– function Table of Contents

• The function array is passed by reference by default
• A function variable is a value pass
• Automatic execution
• Arguments
• Implementing overloading
• anonymous functions

The function array is passed by reference by default

var  arr  = [1, 2, 3]; function  f  (a ) {a[0] = null ;}                         f (ARR); // null 2 3  for  (var  i  = 0; i < 3; i++) {document.write (arr[i]);} 

var arr = [1, 2, 3]; function F (a) {    null;} f (arr);                          1 2 3 for (vari = 0; i < 3; i++) {    document.write (arr[i]);}

A function variable is a value pass

var a = 3; function F (b) {    b = 4;} F (a);d ocument.write (a);           3

Automatic execution

(Funtion () {    varmsg"xxx";    function () {            ...  do something ...    })

Arguments

this . F = function         () {if  (arguments . Length = = 1) {    this . F1 (arguments  [0]); } else  if  ( arguments . Length = = 2) {arguments  [0], arguments  [1]); }}this . F1 = function  (a ) {...} this . F2 = function  (a , b ) {...} 

Arguments.length;arguments[0], arguments[1], Arguments[2]arguments.callee             # callee doesn't look like the outer, it's a closed bag

Alert (function (n) {    if (n <= 1) {        return 1;    Else {        returnarguments. callee (n-1);    }}) (100));

Implementing overloading

function Power (baseexponent) {    varresult = 1;    if undefined) {        exponent = 2;    }     for (vari = 1; I <= exponent; i++) {        result *= base;    }    return result;}

anonymous functions

(function(a) {alert (a);}) (' abc ')

JS--function