JavaScript - count character occurrences

In this article, we would like to show you how to count the number of characters that were used in some text using JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

const countCharacters = (input) => {
	const counts = {};
	for (const entry of input) {
		const count = counts[entry] ?? 0;
		counts[entry] = count + 1;
	}
	return counts;
};


// Usage example:

const input = 'This is some text...';
const counts = countCharacters(input);

for (const key in counts) {
  	console.log(key + ' ' + counts[key]);
}

Output:

T 1
h 1
i 2
s 3
  3
o 1
m 1
e 2
t 2
x 1
. 3