Borislav Hadzhiev
Sat Oct 23 2021·1 min read
Photo by Rob Wilson
To get the last digit of a number:
slice()
method on the string,
passing it -1
as a parameter.slice
method will return the last character in the string.// 👇️ Decimal numbers const num1 = 1357.579; const lastDigit1Str = String(num1).slice(-1); // 👉️ '9' const lastDigit1Num = Number(lastDigit1Str); // 9 // 👇️ Integers const num2 = 1357; const lastDigit2Str = String(num2).slice(-1); // 👉️ '7' const lastDigit2Num = Number(lastDigit2Str); // 👉️ 7
This approach works for integer and float numbers.
The first step is to use the String
object to convert the number to a string,
so we can call the
String.slice
method on it.
0
and the last - str.length - 1
.The only parameter we passed to the slice
method is the start index - the
index at which to start extraction.
-1
, means give me the last character of the string.This is the same as passing string.length - 1
as the start index.
const str = 'Hello World'; const last1 = str.slice(-1); // 👉️ d console.log(last1); const last1Again = str.slice(str.length - 1); // 👉️ d console.log(last1Again);
The slice
method returns a string, so the last step is to convert it back to a
number, using the Number
object.