CODEWITHSUNDEEP
javascriptregexstringtypestypescript
user6123723
user6123723

Reputation: 11116

What's the TypeScript "type" of the input to the match() function

Javascript String Match function

From the above documentation I see that the input to the String.prototype.match() function is "regexp". It's obviously not a string. What is its type?

In TypeScript how can I declare the input variable?

regex:regexp = ^\d{2}\/\d{2}\/\d{4}$

The above obviously throws an error as regexp is not a recognized type. How can I fix it?

Upvotes: 3

Views: 8573

Answers (2)

user663031
user663031

Reputation:

You can look at the type information in lib.d.ts:

/**
  * Matches a string with a regular expression, and returns an array containing the results of that search.
  * @param regexp A variable name or string literal containing the regular expression pattern and flags.
  */
match(regexp: string): RegExpMatchArray;

/**
  * Matches a string with a regular expression, and returns an array containing the results of that search.
  * @param regexp A regular expression object that contains the regular expression pattern and applicable flags.
  */
match(regexp: RegExp): RegExpMatchArray;

You can see that the type for a regular expression is RegExp, and there are two definitions for match, one taking a string, the other a RegExp.

Upvotes: 10

Jorawar Singh
Jorawar Singh

Reputation: 7621

Try this

//inside the class
//this expression is to test valid email

public reg: RegExp = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;

and then you can test it in your class

this.reg.test("expression to test")

//out side the class

let reg = /^\d+$/;
alert(reg.test("sd")); //will alert false

Upvotes: 2

Related Questions