定义和使用
var patt1 = new RegExp("hello");
var patt2 = /world/ ;
test方法
test() 方法检索字符串中的指定值。返回值是 true 或 false。
var pat = /my/;
var str = "this is my code...";
console.log(pat.test(str)); // true
exec方法
exec() 方法检索字符串中的指定值。返回值是被找到的值。如果没有发现匹配,则返回 null。
var pat = /hello/;
console.log(pat.exec("oh hello world")); //返还hello
正则表达式类型
/pattern/attributes
参数 attributes 是一个可选的字符串,常用属性 "g"、"i" ,分别用于指定全局匹配、区分大小写的匹配。
//不区分大小写
var str = "Visit Hunger";
var patt1 = /hunger/i;
console.log(str.match(patt1)); //全局匹配
var str="hello hunger valley! I am hunger"; var patt1=/hunger/g; console.log(str.match(patt1)); //不区分大小写,全局匹配 var str="hello Hunger valley! I am hunger"; var patt1=/hunger/gi; console.log(str.match(patt1));
字符串正则
1. search
字符串查找
var str="Visit W3School!";
console.log(str.search(/w3school/)); //-1 console.log(str.serach(/w3school/i)); // 6
2. match
字符串匹配
var str="1 plus 2 equal 33";
console.log(str.match(/\d+/)); //[1]
console.log(str.match(/\d+/g)); //[1,2,33]
3. replace
字符串替换
var str="Hello JI! oh I am hunger"
console.log(str.replace(/Hunger/, "valley")); console.log(str.replace(/hunger/ig, "hunger"));
4. split
字符串分割
var str = "Hello Hunger , oh I am Hunger";
str.split("");
str.split(/\s+/);
正则写法
var str="Is this all there is?";
var patt1=/[a-h]/g;
console.log(str.match(patt1));
var str="hello jikexueyuan!";
var patt1=/[^jike]/g;
console.log(str.match(patt1));
var str="hello hunger! How are you?";
var patt1=/hello|you/g; c
onsole.log(str.match(patt1));
var str="That‘s hot!";
var patt1=/h.t/g;
document.write(str.match(patt1));
var str="Give 100%!";
var patt1=/\w/g;
document.write(str.match(patt1));
var str="Give 100%!"; var patt1=/\W/g; document.write(str.match(patt1));
var str="Give 100%!";
var patt1=/\d/g;
document.write(str.match(patt1));
var str="Give 100%!"; var patt1=/\D/g; document.write(str.match(patt1));
var str="Is this all there is?";
var patt1=/\s/g; document.write(str.match(patt1));
var str="Is this all there is?"; var patt1=/\S/g; document.write(str.match(patt1));
/\bm/ 匹配 "moon" 中的 ‘m‘;
/oo\b/ 不匹配 "moon" 中的 ‘oo‘,因为 ‘oo‘ 后面的 ‘n‘ 是一个单词字符;
/oon\b/ 匹配 "moon" 中的 ‘oon‘,因为 ‘oon‘ 位于字符串的末端,后面没有单词字符; var str="Hello jikexueyuan";
var patt1=/\bjikexueyuan/g;
document.write(str.match(patt1));
var str="Hello Hunger.\n be a FE.";
var patt1=/\n/g; document.write(str.search(patt1));
var str="Hello HHunger! Hello World!";
var patt1=/H+/g;
document.write(str.match(patt1));
var str="Hello Hunger! Hello World!";
var patt1=/\w+/g; document.write(str.match(patt1));
var str="Hellooo Hunger! Hello World!"; var patt1=/lo*/g; document.write(str.match(patt1))
var str="1, 100 or 1000?"; var patt1=/10?/g; document.write(str.match(patt1));
var str="100, 1000 or 10000?"; var patt1=/\d{4}/g; document.write(str.match(patt1));
var str="100, 1000 or 10000?"; var patt1=/\d{3,4}/g; document.write(str.match(patt1));
var str="100, 1000 or 10000?"; var patt1=/\d{3,}/g; document.write(str.match(patt1));
var str="Is this his"; var patt1=/is$/g; document.write(str.match(patt1));
var str="Is this his"; var patt1=/^Is/g; document.write(str.match(patt1));
常见正则
原文:http://www.cnblogs.com/wyaocn/p/5814779.html