miku86

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# JavaScript Katas: Split In Parts

## Intro 🌐

Problem solving is an important skill, for your career and your life in general.

That's why I take interesting katas of all levels, customize them and explain how to solve them.

## Understanding the Exercise❗

First, we need to understand the exercise!
If you don't understand it, you can't solve it!.

My personal method:

1. Input: What do I put in?
2. Output: What do I want to get out?

### Today's exercise

Today, another `7 kyu` kata,
meaning we slightly increase the difficulty.

Source: Codewars

Write a function `splitInParts`, that accepts two parameters: `myString` and `partLength`.

Given a string, e.g. `"HelloDev"`,
and a number, e.g. `3`,
return the input string split into `partLength`-long parts separated by a space, e.g. `Hel loD ev`.

Input: a string and a number.

Output: a string.

## Thinking about the Solution 💭

I think I understand the exercise (= what I put into the function and what I want to get out of it).

Now, I need the specific steps to get from input to output.

I try to do this in small baby steps:

1. Get a `partLength`-long part of the input string and add a space
2. Do this for every part
3. Add the remaining part to the end
4. Return the string

Example:

• Input: `"HelloDev", 3`
• Get a `3`-long part of the input string and add a space: `"Hel "`
• Get a `3`-long part of the input string and add a space: `"loD "`
• Add the remaining part to the end: `"ev"`
• Return the string: `"Hel loD ev"`
• Output: `"Hel loD ev"`

## Implementation ⛑

``````function splitInParts(myString, partLength) {
let remaining = myString;
let result = "";

// do it only if the remaining string is longer than the parts
while (remaining.length >= partLength) {
// add the next part and a space to the result
result += remaining.slice(0, partLength) + " ";

// remove the added part from the remaining string
remaining = remaining.slice(partLength);
}

// add the last part that was smaller than the part length
result += remaining;

// remove a trailing space
return result.trim();
}
``````

### Result

``````console.log(splitInParts("HelloDev", 3));
// "Hel loD ev" ✅

console.log(splitInParts("HelloDev", 1));
// "H e l l o D e v" ✅
``````

## Playground ⚽

You can play around with the code here

## Next Part ➡️

Great work!

We learned how to use `while`, `slice`, `trim`.

I hope you can use your new learnings to solve problems more easily!

Next time, we'll solve another interesting kata. Stay tuned!

If I should solve a specific kata, shoot me a message here.

If you want to read my latest stuff, get in touch with me!

## Questions ❔

• How often do you do katas?
• Which implementation do you like more? Why?
• Any alternative solution?

Kostia Palchyk • Edited

Okay, this one is easy enough for me..

``````const splitInParts =
(s, n) => s.replace(new RegExp(`.{\${n}}`, 'g'), '\$& ')
``````

Joseph Mawa

Another possible solution.

``````function splitInParts(myString, partLength) {
let ans = "",
i = 0;
while (i < myString.length) {
ans += myString.slice(i, i + partLength) + " ";
i += partLength;
}
return ans.slice(0, -1);
}
``````

let splitInParts = (myString, partLength) => {
let res = ""
let count = 0

``````for (let i = 0; i < myString.length; i += partLength) {
for (let j = i; j < (partLength + count); j++) {
if (myString[j] !== undefined) {
res += myString[j]
}
}
count = (count + partLength)
res += " "
}
console.log(res)
``````

}

Tim West • Edited

Another golf-style solution that doesn't abuse regular expressions 😎

``````const splitInParts = (s, l) => {
s.split('').map((c,i) => (i+1) % l ? c : `\${c} `).join('').trim();
}
``````

Here's the less abusive solution I would actually use:

``````const splitInParts = (s, partLength) => {
const result = [];

for (let start = 0; start < s.length; start += partLength)
result.push(s.slice(start, start + partLength));

return result.join(' ');
}
``````

This works because `String.prototype.slice()` will stop at the end of the string if the second argument index is out of bounds.