JavaScript基本入门语法集合

  创建脚本块

  <script language=”JavaScript”>

  JavaScript code goes here

  </script>

  隐藏脚本代码

  <script language=”JavaScript”>

  <!--

  document.write(“Hello”);

  // -->

  </script>

  浏览器不支持的时候显示

  <noscript>

  Hello to the non-JavaScript browser.

  </noscript>

  链接外部脚本文件

  <script language=”JavaScript” src="/”youname.js"”></script>

  注释脚本

  // This is a comment

  document.write(“Hello”); // This is a comment

  /*

  All of this

  is a comment

  */

  输出到浏览器

  document.write(“<strong>输出内容</strong>”);

  定义变量

  var myVariable = “some value”;

  字符串相加

  var myString = “String1” + “String2”;

  字符串搜索

  <script language=”JavaScript”>

  <!--

  var myVariable = “Hello there”;

  var therePlace = myVariable.search(“there”);

  document.write(therePlace);

  // -->

  </script>

  字符串替换

  thisVar.replace(“Monday”,”Friday”);

  格式化字串

  <script language=”JavaScript”>

  <!--

  var myVariable = “Hello there”;

  document.write(myVariable.big() + “<br>”);

  document.write(myVariable.blink() + “<br>”);

  document.write(myVariable.bold() + “<br>”);

  document.write(myVariable.fixed() + “<br>”);

  document.write(myVariable.fontcolor(“red”) + “<br>”);

  document.write(myVariable.fontsize(“18pt”) + “<br>”);

  document.write(myVariable.italics() + “<br>”);

  document.write(myVariable.small() + “<br>”);

  document.write(myVariable.strike() + “<br>”);

  document.write(myVariable.sub() + “<br>”);

  document.write(myVariable.sup() + “<br>”);

  document.write(myVariable.toLowerCase() + “<br>”);

  document.write(myVariable.toUpperCase() + “<br>”);

  var firstString = “My String”;

  var finalString = firstString.bold().toLowerCase().fontcolor(“red”);

  // -->

  </script>

  创建数组

  <script language=”JavaScript”>

  <!--

  var myArray = new Array(5);

  myArray[0] = “First Entry”;

  myArray[1] = “Second Entry”;

  myArray[2] = “Third Entry”;

  myArray[3] = “Fourth Entry”;

  myArray[4] = “Fifth Entry”;

  var anotherArray = new Array(“First Entry”,”Second Entry”,”Third Entry”,”Fourth Entry”,”Fifth Entry”);

  // -->

  </script>

  数组排序

  <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>

  分割字符串

  <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>

  弹出警告信息

  <script language=”JavaScript”>

  <!--

  window.alert(“Hello”);

  // -->

  </script>

  弹出确认框

  <script language=”JavaScript”>

  <!--

  var result = window.confirm(“Click OK to continue”);

  // -->

  </script>

  定义函数

  <script language=”JavaScript”>

  <!--

  function multiple(number1,number2) {

  var result = number1 * number2;

  return result;

  }

  // -->

  </script>

  调用JS函数

  <a href=”#” onClick=”functionName()”>Link text</a>

  <a href="/”javascript:functionName"()”>Link text</a>

  在页面加载完成后执行函数

  <body onLoad=”functionName();”>

  Body of the page

  </body>

  条件判断

  <script>

  <!--

  var userChoice = window.confirm(“Choose OK or Cancel”);

  var result = (userChoice == true) ? “OK” : “Cancel”;

  document.write(result);

  // -->

  </script>

  指定次数循环

  <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 + “<br>”);

  }

  // -->

  </script>

  设定将来执行

  <script>

  <!--

  function hello() {

  window.alert(“Hello”);

  }

  window.setTimeout(“hello()”,5000);

  // -->

  </script>

  定时执行函数

  <script>

  <!--

  function hello() {

  window.alert(“Hello”);

  window.setTimeout(“hello()”,5000);

  }

  window.setTimeout(“hello()”,5000);

  // -->

  </script>

  取消定时执行

  <script>

  <!--

  function hello() {

  window.alert(“Hello”);

  }

  var myTimeout = window.setTimeout(“hello()”,5000);

  window.clearTimeout(myTimeout);

  // -->

  </script>

  在页面卸载时候执行函数

  <body onUnload=”functionName();”>

  Body of the page

  </body>