Object of JavaScript

JavaScript has a lot of object content, pick a few feel with more of the explanation.

Learn a few and read JavaScript manuals online.

If you want this manual can leave a message, see I will send you. Well, let's summarize my own way of going to the next step.

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1. Object:

(1) All events in JavaScript are objects: strings, arrays, functions .....

(2) Each object has properties and methods.

(3) JS allows you to customize the object.

2. Custom objects:

(1) Define and create an object instance.

(2) Use a function to define the object, and then create a new object instance.

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Example (for 2-(1)):

Method 1:

<script>

People=new Object ();

People.name= "Ying";

People.age= "18";

document.write ("Name:" +people.name+ ", Age:" +people.age);

</script>

Result: Interface print out name: Ying, age:18

Method 2:

<script>

People=new Object ();

people={

Name: "Ying",

Age:18

}

document.write ("Name:" +people.name+ ", Age:" +people.age);

</script>

Result: Interface print out name: Ying, age:18

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Example (for 2-(2)):

<script>

function people (Name,age) {

This.name=name;

This.age=age;

}

Son=new people ("Ying", 18);

document.write ("Name:" +son.name+ ", Age:" +son.age);

</script>

Result: Interface print out name: Ying, age:18

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String String Object

1.string objects:

String objects are used to handle existing strings, and strings can use single or double quotes "spread: Mixed use to avoid collisions." 】。

2. Some properties of the demo:

(1) Finding a string in a string: IndexOf ()

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Example (for 2-(1)):

<script>

var str= "Hello World";

document.write ("string:" +str.length+ "<br/>");

document.write ("World Position:" +str.indexof ("World") + "<br/>");

document.write ("llllll position" Str.indexof ("llllll"));

</script>

Result: The interface prints out the string: 11

World's Position: 6

Lllllll's Location: 1

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(2) Content matching: match ()

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Example (for 2-(2)):

<script>

var str= "Hello World";

document.write (Str.match ("World"));

document.write (Str.match ("lllllll"));

</script>

Result: The interface prints world null

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(3) Replacement content: replace ()

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Example (for 2-(3)):

<script>

var str= "Hello World";

document.write (Str.replace ("World", "123"));

</script>

Result: The interface prints out Hello 123

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(4) string capitalization conversion: toUpperCase ()/toLowerCase ()

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Example (for 2-(4)):

<script>

var str= "Hello World";

document.write (Str.touppercase ());

</script>

Result: The interface prints out Hello World

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(5) Convert string to array: Split ()

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Example (for 2-(5)):

<script>

var str1= "HELLO,JJJ,LLL,KKK";

var s=str1.split (",");//comma as delimiter

document.write (S[1]);

</script>

Result: Interface Print JJJ

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Date Day Object

1.Date objects:

Date objects are used to process dates and times.

2. Obtain the date of the day.

3. Some common methods:

(1) getFullYear (): Gets the year.

(2) GetTime (): Gets the milliseconds.

(3) setFullYear (): Set a specific date.

(4) GetDay (): Get week.

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Example (for 3):

<script>

var date = new Date ();

document.write (date+ "<br/>");

document.write (Date.getfullyear () + "<br/>");

document.write (Date.gettime () + "<br/>");

document.write (Date.getday () + "<br/>");

Date.setfullyear (2010,1,1);

document.write (date);

</script>

Results:

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4. Clock instance:

<script >
function StartTime () {
var today=new Date ();
var h=today.gethours ();
var m=today.getminutes ();
var s=today.getseconds ();
M=checktime (m);
S=checktime (s);
document.getElementById (' txt '). innerhtml=h+ ":" +m+ ":" +s;
T=settimeout (' StartTime () ', 500);//equivalent to T=settimeout (function () {startime;},500)
}

function Checktime (i) {
if (i<10) {

I= "0" + i;

}
return I
}
</script>

<body onload= "StartTime ()" >
<div id= "TXT" ></div>
</body>

Result: Dynamic display time

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Array object:

1.Array objects:

Use a separate variable to store a series of values.

2. Creation of arrays:

Example: Var myarray=["KKK", "ddd", "ddddd"];

3. Access to arrays:

By specifying the array name and the index number, you can access a particular element.

Note: [0] is the first element of the array, and so on. 】

4. Common methods of arrays:

(1) concat (): Merges an array.

(2) sort (): sort.

(3) Push (): Appends the element to the end.

(4) reverse (): array element rollover.

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Example (for 4-(1)):

<script>

var a=["AA", "BB"];

var b=["CC", "DD"];

var c=a.concat (b);

document.write (c);

</script>

Result: The interface prints out the AA bb cc DD

Example (for 4-(2)):

<script>

var a=["A", "C", "D", "T", "B", "E"];

document.write (A.sort ());

</script>

Result: The interface prints a B c e D t

Extension

<script>

var a=["5", "2", "3", "4", "1"];

document.write (A.sort (A, b) {return b-a;})

</script>

Result: The interface prints out 54321. (PS: Because b-a is in reverse order).

Example (for 4-(3)):

<script>

var a=["A", "B"];

A.push (c);

document.write (a);

</script>

Result: Print out ABC

Example (for 4-(4)):

<script>

var a=["C", "B", "a"];

document.write (A.reverse ());

</script>

Result: Print out ABC

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Math object:

1.Match objects:

Perform common arithmetic tasks.

2. Common methods:

(1) Round (): rounded.

(2) Random (): Returns the number of 0~1 between.

(3) Max (): Returns the highest value.

(4) min (): Returns the minimum value.

(5) ABS (): Returns the absolute value.

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Example (for 2-(1)):

document.write (Math.Round (2.5));

Result: The interface prints out 3

Example (for 2-(2)):

document.write (Math.randow ());

Results: The interface randomly prints out a number of 0~1.

document.write (Math.randow () *10);

Results: The interface randomly prints out a number of 1~10.

document.write (parseint (Math.randow ()));

Result: The interface randomly prints out a number of 0~1, and this number is an integer.

Example (for 2-(3)):

document.write (Math.max (10,20,3,90));

Result: The interface prints a maximum value of 90.

Example (for 2-(4)):

document.write (Math.min (12,0,2,3,4));

Result: The interface prints a minimum value of 0.

Example (for 2-(5)):

document.write (Math.Abs (-10));

Result: The interface prints out 10.

Object of JavaScript