1.在地址栏输入JavaScript语句

JavaScript:Document.write("显示文字")

2.将JavaScript嵌入 HTML文档

<script language=JavaScript>
document.bgColor="blue"
</script>

第二章 使用变量和数组

1.声明变量

<script language=javascripe>
Var answer1,answer2,answer3,answer4;
answer1=9;
answer2=2.5
answer3="Milkey May"
answer4=true
</script>

2.使用整数

<script language=JavaScript>
var decimalNum,hexadecimalNum,octalNum
decimalNum=24
hexadecimalNum=0x24
octalNum=024
document.write("显示十进制数："+ decimalNum+"<br>")
document.write("显示十六进制数："+ hexadecimalNum +"<br>")
document.write("显示八进制数："+ octalNum +"<br>")
</script>

3.使用浮点数

<script language=JavaScript>
var num1,num2,num3,num4
num1=1234567890000.0
num2=5.14e23
num3=0.0000123456
num4=6.0254e3-4
document.write("浮点数1："+num1+"<br>")
document.write("浮点数2："+num2+"<br>")
document.write("浮点数3："+num3+"<br>")
document.write("浮点数4："+num4+"<br>")
</script>

4.使用布尔值

<script language=JavaScript>
var answer1,answer2
answer1=true
answer2=false
document.write("显示布尔1："+answer1+"<br>")
document.write("显示布尔2："+answer2+"<br>")
</script>

5.使用字符串

<script language=JavaScript>
var str1,str2
str1="fdsgdg dsfdsf china"
str2="武汉市广播电视大学"
document.write("显示字符串1："+str1+"<br>")
document.write("显示字符串2："+str2+"<br>")
</script>

6.确定变量类型

<script>
var answer1,answer2,answer3,answer4
answer1=9
answer2=2.5
answer3="milky may"
answer4=true
document.write("变量1的类型是："+typeof answer1 +"<br>")
document.write("变量2的类型是："+typeof answer2 +"<br>")
document.write("变量3的类型是："+typeof answer3 +"<br>")
document.write("变量4的类型是："+typeof answer4 +"<br>")
</script>

7.将字符串转换成数字

<script>
var str1="31 days in january"
var int1=parseInt(str1)
document.write("str1的数据类型是 ："+typeof str1+"<br>")
document.write("int1的数据类型是 ："+typeof int1+"<br>")
</script>

8.将数字转换成字符串

<script>
var int1=256
var str1=""+int1
document.write("str1的数据类型是 ："+typeof str1+"<br>")
document.write("int1的数据类型是 ："+typeof int1+"<br>")
</script>

9.声明数组

<script>
array=new Array(5)
array[0]=1
array[1]=3
array[2]=5
array[3]=7
array[4]=11
document.write("数组是："+array[0]+" "+array[1]+" "+array[2]+" "+array[3]+" "+array[4])
</script>

10.确定数组元素的个数

<script>
array=new Array(5)
array[0]=1
array[1]=3
array[2]=5
array[3]=7
array[4]=11
document.write("数组是："+array[0]+" "+array[1]+" "+array[2]+" "+array[3]+" "+array[4]+"<br>")
document.write("数组的元素个数是"+array.length)
</script>