Interview Question #8:
Write a function that will capitalize all words in a sentence.๐ค
If you need practice, try to solve this on your own. I have included 3๏ธโฃ potential solutions below.
Note: There are many other potential solutions to this problem.
Feel free to bookmark ๐ even if you don't need this for now. You may need to refresh/review down the road when it is time for you to look for a new role.
Codepen: If you want to play around and experiment with the code: https://codepen.io/angelo_jin/pen/xxrdBVE
Solution #1: Array Map (Recommended)
- This is one solution I would go by if I am going to be asked in an interview. It pretty straight-forward approach and is legible. ๐ฅ
function capitalize(str) {
return str
.split(' ')
.map(word => word[0].toUpperCase() + word.slice(1)).join(' ');
}
Solution #2: Array Reduce (Recommended)
- Another solution that I like. Array reduce is used as intended where one value is returned as a result of every iteration. Pretty sexy ๐ approach just like array map above.
function capitalize(str) {
return str
.split(' ')
.reduce((prev, current) => `${prev} ${current[0].toUpperCase() + current.slice(1)}`, '')
}
Solution #3: for-of loop
- Below is an alternative solution that can be used but it creates a variable to push results which array reduce solves easily. I see this as an OK option.
function capitalize(str) {
const words = [];
for (let word of str.split(' ')) {
words.push(word[0].toUpperCase() + word.slice(1));
}
return words.join(' ');
}
Happy coding and good luck if you are interviewing!
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Top comments (5)
Love these JS coding questions!
A note on solution #2: instead of putting the whitespace between the prev and current props in the template string (Note: โฌ๏ธ = whitespace so it's easier to see):
${prev}โฌ๏ธ${current[0].toUpperCase() + current.slice(1)}
, '')...you should put the whitespace at the end of the template string:
${prev}${current[0].toUpperCase() + current.slice(1)}โฌ๏ธ
, '')...that way you won't get an empty space before the first word.
What is your solution of choice here? Please share if you have your own solution.
str.replace(/(^|\s)(.)/g,match => match.toUpperCase())
that works beautifully! Thanks for the snippet.
This does the job, no slicing or anything needed.
const capitalize = (sentance) => sentance.toUpperCase();