Go's strings.Count in JavaScript

Here’s what our current JavaScript equivalent to Go's strings.Count looks like.

module.exports = function Count (s, sep) {
// discuss at: https://locutus.io/php/printf/
// original by: Kevin van Zonneveld (https://kvz.io)
// input by: GopherJS (https://www.gopherjs.org/)
// example 1: Count("cheese", "e")
// returns 1: 3
// example 2: Count("five", "") // before & after each rune
// returns 2: 5
let pos
let n = 0
if ((sep.length === 0)) {
return s.split(sep).length + 1
} else if (sep.length > s.length) {
return 0
} else if ((sep.length === s.length)) {
if (sep === s) {
return 1
return 0
while (true) {
pos = (s + '').indexOf(sep)
if (pos === -1) {
n = n + (1) >> 0
s = s.substring((pos + sep.length >> 0))
return n
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How to use

You you can install via npm install locutus and require it via require('locutus/golang/strings/Count'). You could also require the strings module in full so that you could access strings.Count instead.

If you intend to target the browser, you can then use a module bundler such as Parcel, webpack, Browserify, or rollup.js. This can be important because Locutus allows modern JavaScript in the source files, meaning it may not work in all browsers without a build/transpile step. Locutus does transpile all functions to ES5 before publishing to npm.

A community effort

Not unlike Wikipedia, Locutus is an ongoing community effort. Our philosophy follows The McDonald’s Theory. This means that we don't consider it to be a bad thing that many of our functions are first iterations, which may still have their fair share of issues. We hope that these flaws will inspire others to come up with better ideas.

This way of working also means that we don't offer any production guarantees, and recommend to use Locutus inspiration and learning purposes only.


Please note that these examples are distilled from test cases that automatically verify our functions still work correctly. This could explain some quirky ones.

#codeexpected result
1Count("cheese", "e")3
2Count("five", "") // before & after each rune5

Ehm.. Only 4 Go functions in all of Locutus?

We could still assimilate many more functions to this language. We only just rolled out multilingual support to Locutus. If you fancy a challenge, we'd love your help expanding that. For instance, you could:

We will then review it. If it's useful to the project and in line with our contributing guidelines your work will become part of Locutus and you'll be automatically credited in the authors section accordingly.

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