Code base for JavaScript

code base for JavaScript

This article is mainly a collection of some JavaScript in some of the frequently used code. Convenient for later search and reuse.

JavaScript Framework:

<script language= "javascript" type= "Text/javascript" >
JavaScript code
</script>

the definition of a function in JS:

Function name ()

{
function body
}

three major structures:1. Sequential Structure：
2. Select the structure:

if (the result is an expression of type Boolean)

{
The statement that is run when the expression is true.
}
Else

{
The statement that is run when the expression is false.
}

3. Cyclic structure

Loop Initial value
while (loop condition)

{
JavaScript statements that need to be looped
Change the Loop initial value
}

For (initial value of the loop; loop condition; change loop initial value)

{
JavaScript statements that need to be looped
}

operator

Arithmetic operators: +,-, *,/,% (remainder), = (Assignment)

Arithmetic operators:>, >=, <, <=,! =, = =

Logical operators: && () and, | | (OR),! (Take the reverse)

+ =,-=, *=,/=,%=

+ + (self-add 1) 、--(self-minus 1)

//Array

var a=new Array ();
a[0]=5;
a[1]=9;
a[2]=2;
A.sort (); Sort from small to large
Alert ("Length of the array:" +a.length);
Alert (a[0]+ "," +a[1]+ "," +a[2]);

Escape characters:line break: \ n

The form is:. Write between the double slash//. Number of references outside the second slash
. G = Global Lookup (g is global)
. I means ignoring uppercase and lowercase (i is an abbreviation for ignore case)
Match a series of whitespace characters:/^\s+$/g
Match the left and right whitespace characters of the string:/(^\s+) | (\s+$)/g
Match a series of Chinese:/^[\u4e00-\u9f5a]+$/g
Matching numbers can have decimal points:/^\d+ (\.\d+)? $/g
QQ Number 5 digits above/^\d{5,}$/g//Note the curly braces {} are entered here. Not parentheses ().

Email format verification:/\w+ ([-+.] \w+) *@ (\w+ ([-.] \w+) *\.\w+) */g

Other:

var x = document. Table sole name. text box name. Value; The value in the text box exists in the variable x
Document. Table sole name. text box name. Select (); Select all the contents of the text box.
Document. Table sole name. text box name. focus (); The text box gets the focus.

Alert ("Good people"); Popup dialog box

prompt ("Please enter password", "Default value"); Pop-up input box

event : onfocus gets focus onblur loses focus when the onclick Click event onchange drop-down menu changes.

Submit Form : document. Table sole name. Submit ();

get elements by ID : document.getElementById ("id")

The code that is often used in JavaScript is now a collection of these, and many other frequently used code is collected later.

Code base for JavaScript