JavaScript Basic Knowledge Collation _ Basics

1 Creating script blocks
Program code

Copy Code code as follows:

<script language= "JavaScript" >
The JavaScript code is written in this area
</script>

2 Hide Script code
Program code

<script language= "JavaScript" > <!-document.write ("Hello"); -> </script>
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Do not execute related code in browsers that do not support JavaScript
3 When the browser does not support the display
Program code

Copy Code code as follows:

<noscript>
Hello to the Non-javascript browser.
</noscript>

4 linking external script files
Program code

Copy Code code as follows:

<script language= "JavaScript" src= "/" Filename.js "></script>

5 Annotation Scripts
Program code

Copy Code code 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 code as follows:

document.write ("<strong>hello jb51 .net</strong>");

7 Defining variables
Program code

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var myvariable = "some value";

8 String Addition
Program code

Copy Code code as follows:

var myString = "String1" + "String2";

9 String Search
Program code

<script language= "JavaScript" > <!-var myvariable = "Hello There"; var thereplace = Myvariable.search ("there"); document.write (Thereplace); -> </script>
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10 String Replacement
Program code

Copy Code code as follows:

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

11 formatting strings
Program code

<textarea id="runcode65537"><script language= "JavaScript" > <!-var myvariable = "Hello There"; document.write (Myvariable.big () + ""); document.write (Myvariable.blink () + ""); document.write (Myvariable.bold () + ""); document.write (myvariable.fixed () + ""); document.write (Myvariable.fontcolor ("red") + ""); document.write (Myvariable.fontsize ("18pt") + ""); document.write (Myvariable.italics () + ""); document.write (Myvariable.small () + ""); document.write (Myvariable.strike () + ""); document.write (Myvariable.sub () + ""); document.write (Myvariable.sup () + ""); document.write (Myvariable.tolowercase () + ""); document.write (Myvariable.touppercase () + ""); var firststring = "My String"; var finalstring = Firststring.bold (). toLowerCase (). FontColor ("Red"); -> </script></textarea>
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12 Creating an array
Program code

<script language= "JavaScript" > <!-var myarray = new Array (5); Myarray[0] = "Entry"; MYARRAY[1] = "Second Entry"; MYARRAY[2] = "Third Entry"; MYARRAY[3] = "Fourth Entry"; Myarray[4] = "Fifth Entry"; var anotherarray = new Array ("Entry", "Second Entry", "Third Entry", "Fourth Entry", "fifth Entry"); -> </script>
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13 Array Sorting
Program code

<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>
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14 Split String
Program code

<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>
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15 Pop-up warning message
Program code

<script language= "JavaScript" > <!-window.alert ("Hello"); -> </script>
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16 Pop-up confirmation box
Program code

<script language= "JavaScript" > <!-var result = window.confirm ("Click OK to continue"); -> </script>
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17 Custom Functions
Program code

<script language= "JavaScript" > <!-function Multiple (number1,number2) {var result = Number1 * NUMBER2; return result; }//-> </script>
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18 Calling JS function
Program code

Copy Code code as follows:

<a href= "#" onclick= "functionname ()" >link text</a>
<a href= "/" Javascript:functionname "()" >link text</a>

19 Execute function After page load completes
Program code

Copy Code code as follows:

<body onload= "functionname ();" >
The body of the page
</body>

20 piece Judgment
Program code

<script> <!-var userchoice = window.confirm ("Choose OK or Cancel"); var result = (Userchoice = = True)? "OK": "Cancel"; document.write (result); -> </script>
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21 specified number of cycles
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] + ""); }//->
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