I would like to do a regular expression that does not allow more than 1 consecutive spaces.

For example:

• A Bb 7 is valid
• AA O is not valid
• 00 55 is valid
• A b is not valid

CodePudding user response：

Here you can try this logic :

let str = "apple mango pine";

let result = str.match(/ {2,}/g);

if (result) {
  console.log("two consecutive spaces are not allowed");
} else console.log("valid");

CodePudding user response：

Depending on your exact needs I can provide two versions:

This works with only the "space" character, but does not take other spacing characters from Unicode into account:

^[^ ]*(?: [^ ] )* ?$

That takes the regex spacing characters into account, so also uses newlines, tabs etc. as "space":

^\S*(?:\s\S )*\s?$

Both regular expressions match when they find a valid input.

CodePudding user response：

What makes you think you need a regular expression for this?

 if (string.includes('  '))
    alert('error!')