I am trying to limit user's input as followings.

1. English characters (a to z or A to Z)
2. Numeric characters ( 0 to 9 )
3. All special characters (~`!@#$%^&*()_+-=[]{}|;':",./<>?)

I want to prevent user to enter non-english characters (like Chinese, Korean, etc.).

export const isValidPasswordChar = str => {
  const regex = /^[~`!@#$%^&*()_+\-=\[\]\\{}|;':",./<>?a-zA-Z0-9]$/;
  if(regex.test(str)){
    return false
  }
  return true;
};

And unit test

it('should not allow foreign chars-1', ()=>{
    const str = '안';
    expect(isValidPasswordChar(str)).toBe(false);
  });

The above unit test worked before but for some reason, unit test is keep failing. Is there something I am missing here?

I am trying to limit user's input as followings.

1. English characters (a to z or A to Z)
2. Numeric characters ( 0 to 9 )
3. All special characters (~`!@#$%^&*()_+-=[]{}|;':",./<>?)

I want to prevent user to enter non-english characters (like Chinese, Korean, etc.).

export const isValidPasswordChar = str => {
  const regex = /^[~`!@#$%^&*()_+\-=\[\]\\{}|;':",./<>?a-zA-Z0-9]$/;
  if(regex.test(str)){
    return false
  }
  return true;
};

And unit test

it('should not allow foreign chars-1', ()=>{
    const str = '안';
    expect(isValidPasswordChar(str)).toBe(false);
  });

The above unit test worked before but for some reason, unit test is keep failing. Is there something I am missing here?

• javascript
• regex

• 1 You have to repeat the character class using + and escape the backslash ^[~`!@#$%^&*()_+\-=[]\\{}|;':",.\/<>?a-zA-Z0-9]+$ See regex101./r/CGxQhx/1 – The fourth bird Commented Jul 21, 2019 at 10:32

1 Answer 1

You're on right path

^[~`!@#$%^&*()_+=[\]\\{}|;':",.\/<>?a-zA-Z0-9-]+$

• You can move - at end so not needed to escape
• except ] and / and \ you don't need to escape other characters

const isValidPasswordChar = str => {
  const regex = /^[~`!@#$%^&*()_+=[\]\{}|;':",.\/<>?a-zA-Z0-9-]+$/;
  return regex.test(str)
};

console.log(isValidPasswordChar('/'))
console.log(isValidPasswordChar('`1234567890-=;:,./'))
console.log(isValidPasswordChar('HelloPasword1234~!@#$%^&*()_+'))
console.log(isValidPasswordChar('汉字'))