JavaScript基本语法-优快云博客

 
 创建脚本块
<scriptlanguage=”JavaScript”>
JavaScriptcodegoeshere
</script>
隐藏脚本代码
 
<scriptlanguage=”JavaScript”>
<!--
document.write(“Hello”);
 //--> 
</script>
 
浏览器不支持的时候显示
 
<noscript>
Hellotothenon-JavaScriptbrowser.
</noscript>
 
链接外部脚本文件
 
 <scriptlanguage=”JavaScript”src="/”youname.js"”></script> 
 
注释脚本
 
 //Thisisacomment 
 document.write(“Hello”);//Thisisacomment 
 /* 
Allofthis
isacomment
 */ 
 
输出到浏览器
 
document.write(“<strong>输出内容</strong>”);
 
定义变量
 
 varmyVariable=“somevalue”; 
 
字符串相加
 
 varmyString=“String1”+“String2”; 
 
字符串搜索
 
<scriptlanguage=”JavaScript”>
<!--
 varmyVariable=“Hellothere”; 
 vartherePlace=myVariable.search(“there”); 
document.write(therePlace);
 //--> 
</script>
 
字符串替换
 
thisVar.replace(“Monday”,”Friday”);
 
格式化字串
 
<scriptlanguage=”JavaScript”>
<!--
 varmyVariable=“Hellothere”; 
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>”);
 varfirstString=“MyString”; 
 varfinalString=firstString.bold().toLowerCase().fontcolor(“red”); 
 //--> 
</script>
 
创建数组
 
<scriptlanguage=”JavaScript”>
<!--
 varmyArray=newArray(5); 
myArray[0]=“FirstEntry”;
myArray[1]=“SecondEntry”;
myArray[2]=“ThirdEntry”;
myArray[3]=“FourthEntry”;
myArray[4]=“FifthEntry”;
 varanotherArray=newArray(“FirstEntry”,”SecondEntry”,”ThirdEntry”,”FourthEntry”,”FifthEntry”); 
 //--> 
</script>
 
数组排序
 
<scriptlanguage=”JavaScript”>
<!--
 varmyArray=newArray(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
 
<scriptlanguage=”JavaScript”>
<!--
 varmyVariable=“a,b,c,d”; 
 varstringArray=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
 
<scriptlanguage=”JavaScript”>
<!--
window.alert(“Hello”);
 //--> 
</script>
 
弹出确认框
 
<scriptlanguage=”JavaScript”>
<!--
 varresult=window.confirm(“ClickOKtocontinue”); 
 //--> 
</script>
 
定义函数
 
<scriptlanguage=”JavaScript”>
<!--
 functionmultiple(number1,number2){ 
 varresult=number1*number2; 
 returnresult; 
}
 //--> 
</script>
 
调用JS函数
 
<ahref=”#”onClick=”functionName()”>Linktext</a>
 <ahref="/”javascript:functionName"()”>Linktext</a> 
 
在页面加载完成后执行函数
 
<bodyonLoad=”functionName();”>
Bodyofthepage
</body>
 
条件判断
 
<script>
<!--
 varuserChoice=window.confirm(“ChooseOKorCancel”); 
 varresult=(userChoice==true)?“OK”:“Cancel”; 
document.write(result);
 //--> 
</script>
 
指定次数循环
 
<script>
<!--
 varmyArray=newArray(3); 
myArray[0]=“Item0”;
myArray[1]=“Item1”;
myArray[2]=“Item2”;
 for(i=0;i<myArray.length;i++){ 
document.write(myArray+“<br>”);
}
 //--> 
</script>
 
设定将来执行
 
<script>
<!--
 functionhello(){ 
window.alert(“Hello”);
}
window.setTimeout(“hello()”,5000);
 //--> 
</script>
 
定时执行函数
 
<script>
<!--
 functionhello(){ 
window.alert(“Hello”);
window.setTimeout(“hello()”,5000);
}
window.setTimeout(“hello()”,5000);
 //--> 
</script>
 
取消定时执行
 
<script>
<!--
 functionhello(){ 
window.alert(“Hello”);
}
 varmyTimeout=window.setTimeout(“hello()”,5000); 
window.clearTimeout(myTimeout);
 //--> 
</script>
 
在页面卸载时候执行函数
<bodyonUnload=”functionName();”>
Bodyofthepage
</body>
 