验证正则表达式中的字符串

Question

I want to have a regular expression in JavaScript which help me to validate a string with contains only lower case character and and this character - .

I use this expression:

var regex = /^[a-z][-\s\.]$/

It doesn't work. Any idea?

Answer 1

Simple, just use: /^[az-]+$/

Explanation:

• ^ : Match from beginning string
• [az-] : Match all character between az and -
  • [] : Only characters within brackets are allowed
  • az : Match all character between az. Ex: p,s,t
  • - : Match only strip ( - ) character
• + : Shorthand for {1,} . The means is match 1 or more
• $ : Match until end of the string

Example:

 const regex= /^[az-]+$/ console.log(regex.test("abc")) // true console.log(regex.test("aBcD")) // false console.log(regex.test("ac")) // true

Answer 2

Try this:

var regex = /^[-a-z]+$/;

 var regex = /^[-az]+$/; var strs = [ "a", "aB", "abcd", "abcde-", "-", "-----", "abc", "aDc", " " ]; strs.forEach(str=>console.log(str, regex.test(str)));

Answer 3

Try this

/^[a-z-]*$/

it should match the letters az or - as many times as possible.

What you regex does is trying to match az one single time, followed by any of -, whitespace or dot one single time. Then expect the string to end.

Answer 4

Use this regular expression:

let regex = /^[a-z\-]+$/;

Then:

regex.test("abcd") // true
regex.test("ab-d") // true
regex.test("ab3d") // false
regex.test("") // false

PS: If you want to allow empty string "" to pass, use /^[az\-]*$/ . Theres an * instead of + at the end. See Regex Cheat Sheet: https://www.rexegg.com/regex-quickstart.html

Answer 5

This will work:

 var regex = /^[az|\-|\s]+$/ //For this regex make use of the 'or' | operator str = 'test- '; str.match(regex); //["test- ", index: 0, input: "test- ", groups: undefined] str = 'testT- ' // string now contains an Uppercase Letter so it shouldn't match anymore str.match(regex) //null

Answer 6

I hope this helps

 var str = 'asdadWW--asd'; console.log(str.match(/[az]|\-/g));