Typescript ES5 Function

Codewars task:

You ask a small girl,"How old are you?" She always says, "x years old", where x is a random number between 0 and 9.

Write a program that returns the girl's age (0-9) as an integer.

Example:

Assume the test input string is always a valid string. For example, the test input may be "1 year old" or "5 years old". The first character in the string is always a number.

Solution:

export const get_age = (age: string): number => Number(age[0])

get_age('4 years old')                                // Output: 4

Explanation:

The function takes the first character of the age string and converts it to a number using the Number() function. This means that the function assumes that the first character of the age string is a number and will return that number as a result.