Count Characters

Easy

Count Characters

Easy

Write a function that takes a string and returns an object that counts the number of occurrences of each character in the string using a for loop.

For example, if we call countCharacters('hello')
, the function would return the following object:

{
  h: 1,
  e: 1,
  l: 2,
  o: 1
}

Console

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Solution

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Solution Walkthrough for Count Characters

Spoiler Alert!

Don't read this unless you've already solved the problem.

countCharacters
that takes a string str
as an argument and returns an object that counts the number of occurrences of each character in the input string using a for loop.

Here's how it works:

Inside the loop, the function uses the charAt()
method to get the character at the current index i
in the string, and assigns it to a variable called char
.

const char = str.charAt(i);

The function then checks if the current character already exists as a key in the counts
object. If it does, it increments its count by 1. If it doesn't, it sets its count to 1.

counts[char] = counts[char] ? counts[char] + 1 : 1;

This line of code uses a ternary operator to check if counts[char]
is truthy. If it is, it increments its value by 1 (counts[char] + 1
). If it's falsy (i.e. undefined), it sets its value to 1.

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