/**
 * 
 * Ashish Patel
 * e: ashishsushilPatel@gmail.com
 * w: https://ashish.me
 *
 */

/* 
Find the leftmost digit that occurs in a given string.

Example

For inputString = "var_1__Int", the output should be firstDigit(inputString) = '1';

For inputString = "q2q-q", the output should be firstDigit(inputString) = '2';

For inputString = "0ss", the output should be firstDigit(inputString) = '0'.
*/

function firstDigit(str) {
  const digits = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']
  str = str.split('')
  for (let index = 0; index < str.length; index++) {
    if(digits.includes(str[index])){
      return str[index]
    }
  }
}

test('first Digit', () => {
  expect(firstDigit('var_1__Int')).toEqual('1')
  expect(firstDigit('q2q-q')).toEqual('2')
  expect(firstDigit('0ss')).toEqual('0')
});