JS Basic Knowledge Summary (All)

Version 1.js HelloWorld

<script type= "Text/javascript" >

Alert ("HelloWorld");

</script>

2. Notes

Single-line//

Multi-line/**/

3. Operators

+ 、-、 *,/,%, + =,-=, = = (same value), = = = (same type and value)

4. Logical operators

| |, &&

5. Defining variables (weakly typed)

var num= 1;

var string = "I am Chinese";

var Myboolean = true;

6. Method (defined by function)

<script type= "Text/javascript" >

function Fun (A, b) {

alert (A+B);

}

Fun ("Iam", "Chinese");

</script>

7. Process Control Statements

if () {}else{}

while () {}

Do{}while ()

Switch () {case 1:break;case 2:break;default:3;}

Continue end Current loop, enter Next loop

Break Exit Loop

8.js objects

var obj = new Object ();

Obj.name = "Tom";

Obj.age = 18;

function Fun (A, b) {

Return a + ":" +B;

}

Obj.myfun = fun;

Alert (Obj.myfun (obj.name,obj.age));

9.undefine, NULL

Undefine defined variable has no value assigned to it as Undefine

var A;

alert (a);//result is undefine

Null to place the variable null

var b=1;

b = null;

alert (b);//result is null

10. Common methods

Manipulating the String class

Manipulating the Date class

　　

JS Basic Knowledge Summary (All)