How Can I Check if One String Starts With Another in JavaScript?

Determining String Precedence with "StartsWith"

Question: How can I ascertain if one string initiates with another in JavaScript, akin to the String.StartsWith method in C#?

JavaScript Equivalent to C#'s String.StartsWith

Prior to ECMAScript 2015 (ES6), JavaScript lacked a native method similar to String.StartsWith. However, ES6 introduced the String.prototype.startsWith() method.

Browser Support:

Note that as of this writing (2015), comprehensive browser support for String.prototype.startsWith() remains insufficient. Therefore, support may be required in browsers that lack native implementation.

Shimming for Unsupported Browsers:

For browsers without native String.prototype.startsWith() support, shims or polyfills can be utilized to provide functionality. Two recommended options are:

• Matthias Bynens's String.prototype.startsWith shim
• The es6-shim, which incorporates a wide range of ES6 features, including String.prototype.startsWith().

Usage after Shimming or for Supported Browsers:

Once method support is ensured, String.prototype.startsWith() can be employed as follows:

console.log("Hello World!".startsWith("He")); // true

var haystack = "Hello world";
var prefix = 'orl';
console.log(haystack.startsWith(prefix)); // false

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