Regularly intercept/replace a string between two characters

regular expression

• A regular expression used to match strings

Create a regular object

• Constructor
  • var reg = new RegExp(regular expression, matching pattern);

    new RegExp(pattern,attributes);
    参数：参数pattern是一个字符串，指定了正则表达式的模式；
    参数attributes是一个可选的参数，包含属性 g(globle全局匹配),i(忽略大小写),m(多行匹配)

• literal
  • var reg = /regular rule/matching pattern;

Call matching method

• test most commonly uses a regular object to match a certain string
  • If the match is successful, get true, otherwise false
  • Regular object.test(string)

    例：匹配字符串中出出现连续的三个小写a
    var reg = new RegExp(/a{3}/);
    console.log(reg.test("aaac")); //true
    console.log(reg.test("baaab"));//true
    console.log(reg.test("aa"));//false
    console.log(reg.test("AAA"));//false

• match is used to match a certain string
  • String.match(regular expression)
  • Return value: array – containing the matched string and the index of the matched original string

    例：匹配字符串中是否包含连续的三个小写a
    console.log("aaabcdefaaaghjiy".match(/a{3}/));

• exec
  • Used to match strings
  • Regular object.exec(string) return value is the same as match

Intercept/replace a string between two characters

const str = '/detail/page-1.html'
// 获取
str.match(/page-(\S*).html/)[1]
// 替换
str.replace(/(?<=page-).*?(?=.html)/, 2)