Compilation of javascript basic knowledge_Basic knowledge

1 Create script block
Program code

Copy code The code is as follows:

2 Hide script code
Program code

[Ctrl A Select all Note: If you need to introduce external Js, you need to refresh to execute

]

In browsers that do not support JavaScript The relevant code will not be executed in the browser3. When the browser does not support it, it will be displayed

Program code

Copy code

The code is as follows:

4 Link external script files
Program code

Copy code

The code is as follows:

5 Comment Script

Program Code

Copy code

The code is as follows:

// This is a comment
document. write("Hello"); // This is a comment
/*
All of this
is a comment
*/

6 output to Browser

Program code

Copy code

The code is as follows:

document. write("Hello jb51 .net");

7 Define variables

Program code

Copy code

The code is as follows:

var myVariable = "some value";

8 String addition
Program code

Copy code

The code is as follows:

var myString = "String1" "String2";

9 String search
Program code

[Ctrl A Select all Note:

If you need to introduce external Js, you need to refresh to execute
]
10 string Replace

program codeCopy code

The code is as follows:

thisVar.replace ("Monday","Friday");

11 Format string

Program code

[Ctrl A select all Note: If you need to introduce external Js, you need to refresh to execute ]
12 创建数组
程序代码

<script language="JavaScript"> <!- var myArray = new Array(5); myArray[0] = "First Entry"; myArray[1] = "Second Entry"; myArray[2] = "Third Entry"; myArray[3] = "Fourth Entry"; myArray[4] = "Fifth Entry"; var anotherArray = new Array("First Entry","Second Entry","Third Entry","Fourth Entry","Fifth Entry"); // -> </script>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

13 数组排序
程序代码

<script language="JavaScript"> <!- var myArray = new Array(5); myArray[0] = "z"; myArray[1] = "c"; myArray[2] = "d"; myArray[3] = "a"; myArray[4] = "q"; document.write(myArray.sort()); // -> </script>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

14 分割字符串
程序代码

<script language="JavaScript"> <!- var myVariable = "a,b,c,d"; var stringArray = myVariable.split(","); document.write(stringArray[0]); document.write(stringArray[1]); document.write(stringArray[2]); document.write(stringArray[3]); // -> </script>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

15 弹出警告信息
程序代码

<script language="JavaScript"> <!- window.alert("Hello"); // -> </script>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

16 弹出确认框
程序代码

<script language="JavaScript"> <!- var result = window.confirm("Click OK to continue"); // -> </script>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

17 自定义函数
程序代码

<script language="JavaScript"> <!- function multiple(number1,number2) { var result = number1 * number2; return result; } // -> </script>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

18 调用JS函数
程序代码

复制代码 代码如下:

Link text
Link text

19 在页面加载完成后执行函数
程序代码

复制代码 代码如下:

Body of the page

20 条件判断
程序代码

<script> <!- var userChoice = window.confirm("Choose OK or Cancel"); var result = (userChoice == true) ? "OK" : "Cancel"; document.write(result); // -> </script>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]

21 specified times of loop
Program code

<script> <!- var myArray = new Array(3); myArray[0] = "Item 0"; myArray[1] = "Item 1"; myArray[2] = "Item 2"; for (i = 0; i < myArray.length; i ) { document.write(myArray[i] " "); } // -> </script>
[Ctrl A select all Note: If you need to introduce external Js, you need to refresh to execute ]