If you missed the introductory post, it's here. For a list of previously solved katas, please refer to the bottom of this page.
If this is your first time seeing my post, please note - these katas are probably randomly assigned per user so please don't go into Codewars thinking we will have exactly the same user experience, I am just posting these in the order that I got them.
Kata #11
DESCRIPTION:
Welcome. In this kata, you are asked to square every digit of a number and concatenate them.
For example, if we run 9119 through the function, 811181 will come out, because 9^2 is 81 and 1^2 is 1.
Note: The function accepts an integer and returns an integer
Starting code:
function squareDigits(num){
return 0;
}My attempt that worked:
function squareDigits(num){
let numToArr = Array.from(num.toString())
let strHolder = ""
for (i=0;i<numToArr.length;i++){
strHolder += (numToArr[i]**2)
}
return Number(strHolder);
}The challenges before this one were at 8 kyu rank, this is the first 7 kyu problem that I got.
Rank #1 'Best Practice':
function squareDigits(num){
return Number(('' + num).split('').map(function (val) { return val * val;}).join(''));
}Rank #2:
function squareDigits(num){
return +num.toString().split('').map(i => i*i).join('');
}Rank #3 which shows how to do it with the parseInt() function:
function squareDigits(num){
var array = num.toString().split('').map( function(int) {
var i = parseInt(int);
return i * i;
});
return parseInt(array.join(""));
}Rank #4 where I think my approach kinda sorta falls under, except I didn't use the .join() method:
function squareDigits(num){
var string = num.toString();
var results = [];
for (var i = 0; i < string.length; i++){
results[i] = string[i] * string[i];
}
return Number(results.join(''));
};That's it for Kata #11, stay tuned for more katas to be solved!
Link to Kata #1: Square(n) Sum
Link to Kata #2: Convert a Number to a String
Link to Kata #3: DNA to RNA Conversion
Link to Kata #4: Remove First and Last Character
Link to Kata #5: MakeUpperCase
Link to Kata #6: Total amount of points
Link to Kata #7: A Needle in the Haystack
Link to Kata #8: Sum of positive
