JS基础知识整理
1 创建脚本块
引用内容程序代码
<script language=”JavaScript”>
JavaScript 代码写在这里面
</script>
2 隐藏脚本代码
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<script language=”JavaScript”>
<!–
document.write(“Hello”);
// –>
</script>
在不支持JavaScript的浏览器中将不执行相关代码
3 浏览器不支持的时候显示
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<noscript>
Hello to the non-JavaScript browser.
</noscript>
4 链接外部脚本文件
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<script language=”JavaScript” src=”/”filename.js””></script>
5 注释脚本
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// This is a comment
document.write(“Hello”); // This is a comment
/*
All of this
is a comment
*/
6 输出到浏览器
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document.write(“<strong>Hello</strong>”);
7 定义变量
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var myVariable = “some value”;
8 字符串相加
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var myString = “String1” + “String2”;
9 字符串搜索
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<script language=”JavaScript”>
<!–
var myVariable = “Hello there”;
var therePlace = myVariable.search(“there”);
document.write(therePlace);
// –>
</script>
10 字符串替换
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thisVar.replace(“Monday”,”Friday”);
11 格式化字串
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<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>
12 创建数组
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<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>
13 数组排序
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<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>
14 分割字符串
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<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>
15 弹出警告信息
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<script language=”JavaScript”>
<!–
window.alert(“Hello”);
// –>
</script>
16 弹出确认框
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<script language=”JavaScript”>
<!–
var result = window.confirm(“Click OK to continue”);
// –>
</script>
17 自定义函数
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<script language=”JavaScript”>
<!–
function multiple(number1,number2) {
var result = number1 * number2;
return result;
}
// –>
</script>
18 调用JS函数
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<a href=”#” onClick=”functionName()”>Link text</a>
<a href=”/”javascript:functionName”()”>Link text</a>
19 在页面加载完成后执行函数
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<body onLoad=”functionName();”>
Body of the page
</body>
20 条件判断
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<script>
<!–
var userChoice = window.confirm(“Choose OK or Cancel”);
var result = (userChoice == true) ? “OK” : “Cancel”;
document.write(result);
// –>
</script>
21 指定次数循环
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<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] + “<br>”);
}
// –>
</script>
22 设定将来执行
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<script>
<!–
function hello() {
window.alert(“Hello”);
}
window.setTimeout(“hello()”,5000);
// –>
</script>
23 定时执行函数
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<script>
<!–
function hello() {
window.alert(“Hello”);
window.setTimeout(“hello()”,5000);
}
window.setTimeout(“hello()”,5000);
// –>
</script>
24 取消定时执行
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<script>
<!–
function hello() {
window.alert(“Hello”);
}
var myTimeout = window.setTimeout(“hello()”,5000);
window.clearTimeout(myTimeout);
// –>
</script>
25 在页面卸载时候执行函数
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<body onUnload=”functionName();”>
Body of the page
</body>
JavaScript就这么回事2：浏览器输出
26 访问document对象
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<script language=”JavaScript”>
var myURL = document.URL;
window.alert(myURL);
</script>
27 动态输出HTML
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<script language=”JavaScript”>
document.write(“<p>Here’s some information about this document:</p>”);
document.write(“<ul>”);
document.write(“<li>Referring Document: “ + document.referrer + “</li>”);
document.write(“<li>Domain: “ + document.domain + “</li>”);
document.write(“<li>URL: “ + document.URL + “</li>”);
document.write(“</ul>”);
</script>
28 输出换行
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document.writeln(“<strong>a</strong>”);
document.writeln(“b”);
29 输出日期
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<script language=”JavaScript”>
var thisDate = new Date();
document.write(thisDate.toString());
</script>
30 指定日期的时区
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<script language=”JavaScript”>
var myOffset = -2;
var currentDate = new Date();
var userOffset = currentDate.getTimezoneOffset()/60;
var timeZoneDifference = userOffset – myOffset;
currentDate.setHours(currentDate.getHours() + timeZoneDifference);
document.write(“The time and date in Central Europe is: “ + currentDate.toLocaleString());
</script>
31 设置日期输出格式
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<script language=”JavaScript”>
var thisDate = new Date();
var thisTimeString = thisDate.getHours() + “:” + thisDate.getMinutes();