Junior Developer Central JS Practice Exercise - 15

 

Question: 

Write a Javascript program to replace the first digit in a string with $ character. 

Answer: 

function replaceFirstDigit (str) {
const newStr = str.replace(/[0-9]/, '$'); 

console.log (newStr); 
}

> we declare a function 'replaceFirstDigit' 

> it has one parameter 'str' which is a string

> we need to replace only the first digit occurrence in the 'str' string with a '$' sign 

> we declare a variable 'newStr' 

> we initialize it with a value that we get by using the replace method on 'str' 

> we use the character class or ''RegExp [0-9] Expression'' to find the digit in 'str' 

> we do not use the modifier 'g' as it will search for all the digits

> we only want the first occurrence so we will use on '/[0-9]/' & not '/[0-9]/g'

> we use '$' sign as the replacement

> we then console.log the 'newStr' variable to get our answer