第三章 创建表达式
1.使用算术运算符
<script> var1=12 var2=10 varadd=var1+var2 varsub=var1-var2 varmult=var1*var2 vardiv=var1/var2 varmod=var1%var2 document.write("数据1是:"+var1+"<br>") document.write("数据2是:"+var2+"<br>") document.write("数据相加是:"+varadd+"<br>") document.write("数据相减是:"+varsub+"<br>") document.write("数据相乘是:"+varmult+"<br>") document.write("数据相除是:"+vardiv+"<br>") document.write("数据相除取余数是:"+varmod+"<br>") </script>
2.递增变量和递减变量
<script> days=1 document.write("输出变量"+days+"<br>") days++ document.write("递增后变量变为:"+days) </script>
3.创建比较表达式
<script> daysofmonth=28 if(daysofmonth==28) month="february" document.write("days of month:"+daysofmonth+"<br>") document.write("month:"+month) </script>
4.创建逻辑表达式
<script> dayofmonth=28 if(dayofmonth==28 || dayofmonth==29) month="february" document.write("days of month:"+dayofmonth+"<br>") document.write("month:"+month) </script>
5.使用条件运算符
<script language="javascript"> stomach="hungry"; time="5:00"; (stomach=="hungry"&&time=="5:00") ? eat = "dinner":eat="a snack"; document.write("输出结果"+eat); </script>
6.识别数字
<script> var1=24; (isNaN(var1))?document.write("变量var1"+var1+"不是数字"):Document.write("变量var1"+var1+"是数字") </script>
第四章 控制程序流程
1.使用IF –Else语句
<script> month="december" date=25 if(month=="december" && date==25) document.write("今天是圣诞节,商店关门") else document.write("欢迎,您来商店购物") </script>
2.使用for 循环
<script> for (count=1;count<=10;count++) document.write("输出第"+count+"句"+"<br>") </script>
3.使用while循环
<script> count=1 while(count<=15){ document.write("输出第"+count+"句" +"<br>") count++} </script>
4.中断循环
<script> count=1 while(count<=15){ count++ if(count==8) break; document.write("输出第"+count+"句"+"<br>")} </script>
5.继续循环
<script> count=1 while(count<=15){ count++ if(count==8) continue; document.write("输出第"+count+"句"+"<br>")} </script>
6.使用javascript定时器
<script> function rabbit() {document.write("输出语句") } </script> <body onload=window.setTimeout(rabbit(),5000)>
7.设置定期间隔
<script> window.setInterval("document.form1.text2.value=document.form1.text1.value",3000) </script> <form name=form1> <input type=text name=text1><br> <input type=text name=text2><br> </form>
8.清除超时和间隔
<script> stop=window.setInterval("document.form1.text2.value=document.form1.text1.value",300) </script> <form name=form1> <input type=text name=text1><br> <input type=text name=text2><br> <input type=button name=button1 value=" 清除超时和间隔" onclick=clearInterval(stop)> </form>
出处:蓝色理想
责任编辑:moby
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