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Javascript
First, what is JavaScript?
Script Description Language, Web Interactive effects, plainly, is the implementation of HTML can not achieve the effect. (JavaScript is an object-based, event-driven, simple scripting language embedded in an HTML document that is interpreted and executed by the browser, creating a dynamic display on a Web page and interacting with the user.) )
Html:
Hypertext Markup Language
Css:
Web page Style
Javascript:
Web Interactive effects
Second, why use JavaScript?
Solve the problems we can not solve now, for example, the form of timely verification, picture carousel ...
Third, the syntax:
<script type= "Text/javascript" >
</script>
1, document.write ("hello!!");
On the Web page output hello!!, in fact this equivalent is: System.out.print ();
2, the Process Control in Java, the same use in JavaScript.
3. Three kinds of pop-up windows
A, alert ();----used more, test
Warning pop-up window, only content and OK button
B, confirm ();
Prompt window, with content, OK and Cancel buttons, click OK, return True, click Cancel
returns false;
C, prompt ();
User Input window, with prompt, input box, OK and Cancel button, click OK, return
The contents of the text box, click Cancel, return null
Four, the code demonstration case:
1, output 1000 times in the page good study day up
123<meta http-equiv= "Content-type" content= "text/html; Charset=utf-8 "/>4<title> second question </title>5<script type= "Text/javascript" >6 for(vari=1;i<=1000;i++){7document.write ("+i+") "+" good study, every day fooled!!! <br/> ");8 }9</script>Ten One A<body> -</body> - the -Output 1000 times in the page good study day
2. Achieve Calculator effect
123<meta http-equiv= "Content-type" content= "text/html; Charset=utf-8 "/>4<title> Untitled Document </title>5<script type= "Text/javascript" >6 varNUM1 =window.prompt ("1, addition; 2, subtraction; 3, multiplication; 4, Division;"));7 varNum2 =window.prompt ("Please enter first number");8 varnum3 =window.prompt ("Please enter a second number");9 varA =parseint (NUM1);Ten varb =parseint (num2); One varc =parseint (num3); A vard = 0; - Switch(a) { - Case1: theD = B +C; - Break; - Case2: -D = bC; + Break; - Case3: +D = b*C; A Break; at Case4: -D = b/c; - Break; - } -document.write ("result is:" +d); -</script> in - to<body> +</body> - the *Implementing the Calculator effect
3. Pop-up window demo case
12<meta http-equiv= "Content-type" content= "text/html; Charset=utf-8 "/>3<title> Untitled Document </title>45<script type= "Text/javascript" >6 //alert ("123");//Warning pop-up window7 //Window.alert ("321");8 //var q = window.confirm ("456");//with OK and cancel popup, click OK, return True, click Cancel, return False9 //document.write (q);Ten //var a = window.prompt ("Please Enter Name:", "small Black");//can implement user input pop-up window, click OK, return the contents of the input box, click Cancel, return null One //document.write (a); A //var t = ""; - //While (t!= "small Black") { - //t = window.prompt ("Please enter Name:"); the //} - varnum = window.prompt ("Please enter a value of 1-9"); - if(num>1&&num<=9){ - for(vari = 1;i<=num;i++){ + for(varj = 1;j<=i;j++){ -document.write ("*"); + } Adocument.write ("<br/>"); at } -}Else{ -Alert ("Please enter correctly"); - } -</script> -<body> in</body> - to +Pop-up window demo case
4. Comprehensive demonstration Cases
123<meta http-equiv= "Content-type" content= "text/html; Charset=utf-8 "/>4<title> Untitled Document </title>5 67<script type= "Text/javascript" >8 for(varI =1;i<=4;i++){9 for(varK = 3;k>=i;k--){Tendocument.write (" "); One } A for(varj = 1;j<=2*i-1;j++){ -document.write ("*"); - } thedocument.write ("<br/>"); - } - for(vari = 1;i<=3;i++){ - for(varK = 0;k<i;k++){ +document.write (" "); - } + for(varK = 3;k>=i;k--){ Adocument.write ("*"); at } - for(varK = 3;k>i;k--){ -document.write ("*"); - } -document.write ("<br/>"); - } indocument.write ("-----------------------I am the split line-the cumulative value of output 1-100, skipping 3 digits--------------<br/>"); - varsum = 0; to for(vari = 1;i<=100;i++){ + if(i%10!=3){ -sum = sum +i; the } * } $document.write ("sum=" +sum);Panax Notoginsengdocument.write ("<br/>-----------------------I'm a split line-chicken and rabbit cage--------------<br/>"); - for(varJi = 0;ji<=24;ji++){ the varTu = 24-ji; + if(ji*2+tu*4==60){ Adocument.write ("Chickens have" +ji+ "only, rabbits have" +tu); the } + } -document.write ("<br/>-----------------------I am the dividing line-classical question--------------<br/>"); $ varStart=1; $ varNext=1; - for(vari=3;i<13;i++){ - vartemp=start+Next; thestart=Next; -next=temp;Wuyi the - Document.writeln (next); Wu } -</script> About<body> $</body> - -Comprehensive Demo case
JavaScript Basics (i)
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