Web_正则表达式

1创建正则表达式

⚫var exp = new RegExp(pattern [, attributes] );
⚫var exp1=new RegExp("正则表达式");
⚫var exp2=new RegExp("正则表达式", "i");
⚫var exp3=new RegExp("正则表达式", "ig");
⚫var exp = /正则表达式/;
⚫var exp = /正则表达式/ig

1.1RegExp方法

var pattern = new RegExp("java", "i");
var str="I like java.";
alert(pattern.test(str)); //true
var pattern = /java/ig;
var str="I like java, also like javascript.";
alert(pattern.exec(str)); //java

1.2String类型的方法

var regExp=new RegExp("\\d+","g");
var str="123abc345de434fg";
document.write(str.replace(regExp, "#")); //#abc#de#fg
document.write("<br>");
document.write(str.replace(/\d+/g, "#")); //#abc#de#fg

2元字符

3例题1：检验Email

规则
[email protected]
[email protected]
^([a-zA-Z0-9_-])+@[a-zA-Z0-9_-]+((.[a-z]{2,8}){1,2})$
检验Email

function checkEmail() {
var email=document.myForm.myEmail.value;
var reg=/^([a-zA-Z0-9_-])+@[a-zA-Z0-9_-]+((\.[a?z]{2,8}){1,2})$/;
if(reg.test(email)) {
alert("Email格式正确!");
return true;
}
else {
alert("Email格式不符!");
return false;
}
}

4例题2：检验电话号码

座机规则
1.010-12345678
2.0755-12345678
3.0535-1234567
4.12345678
5.1234567

^((0[1-9][0-9]-)?[1-9][0-9]{7}|(0[1-9][0-9]{2}-)?([1-9][0-9]{6,7}))$