CODEWITHSUNDEEP
javascriptregexswitch-statement
Logan MacDougall
Logan MacDougall

Reputation: 149

How do I test for the result of a regular expression in a switch in JavaScript

I was wondering why the result of my regular expression wasn't going to the case I wanted to go through.

var r = "This is a test.";
var ex = /a/g;
var l = ex.exec(r);

alert(l);

switch (l)
{
    case "a":
      alert("good");
      break;

    default:
      alert("error");
}

If you run this, you can see that "l" does in fact does equal "a" which then should trigger the case function. If anyone knows why it isn't, please help. Thank you

Upvotes: 1

Views: 75

Answers (3)

Priyal Pithadiya
Priyal Pithadiya

Reputation: 889

@LoganMacMonkey, the type return by var l = ex.exec(r); is array. Refer this and you try to compare array with string using switch case structure. Due to this reason your code is not working

To resolve it Convert 

 switch (l)

To the,

 switch(l.toString())

Hope it you are looking for the same!! :)

Upvotes: 0

Miguel
Miguel

Reputation: 1656

In regular expressions you have matches, To check the matches that your regex is generating use console.log, the devtool built-in debugger or pages like https://regex101.com/

Upvotes: 0

CertainPerformance
CertainPerformance

Reputation: 370979

Test against l[0] instead to get the matched substring:

var r = "This is a test.";
var ex = /a/g;
var l = ex.exec(r);

switch (l[0])
{
    case "a":
      alert("good");
      break;

    default:
      alert("error");
}

Upvotes: 3

Related Questions