How to check if a string "StartsWith" another string?
javascript, startswith, string
Solution
You can use ECMAScript 6's `String.prototype.startsWith()` method. It's supported in all major browsers. However, if you want to use it in a browser that is unsupported you'll want to use a shim/polyfill to add it on those browsers. Creating an implementation that complies with all the details laid out in the spec is a little complicated. If you want a faithful shim, use either:
- Matthias Bynens's `String.prototype.startsWith` shim, or
- The es6-shim, which shims as much of the ES6 spec as possible, including `String.prototype.startsWith`.
Once you've shimmed the method (or if you're only supporting browsers and JavaScript engines that already have it), you can use it like this:
console.log("Hello World!".startsWith("He")); // true
var haystack = "Hello world";
var prefix = 'orl';
console.log(haystack.startsWith(prefix)); // false
Problem
How would I write the equivalent of C#'s `String.StartsWith` in JavaScript? ``` var haystack = 'hello world'; var needle = 'he'; haystack.startsWith(needle) == true ``` Note: This is an old question, and as pointed out in the comments ECMAScript 2015 (ES6) introduced the `.startsWith` method. However, at the time of writing this update (2015) browser support is far from complete.