NOTE: Modern JavaScript already guarantees Array#sort() is a stable sort, so this library has very little use and has been archived.

See the compatibility table on MDN for the exact versions of JavaScript runtimes that implement stable sort natively.

A stable array sort, because Array#sort() is not guaranteed stable.

MIT licensed.

Install with:

npm install stable

Then use it in Node.js or some other CommonJS environment as:

const stable = require('stable')

Include stable.js or the minified version stable.min.js in your page, then call stable().

The default sort is, as with Array#sort, lexicographical:

stable(['foo', 'bar', 'baz'])  // => ['bar', 'baz', 'foo']
stable([10, 1, 5])             // => [1, 10, 5]

Unlike Array#sort, the default sort is NOT in-place. To do an in-place sort, use stable.inplace, which otherwise works the same:

const arr = [10, 1, 5]
stable(arr) === arr          // => false
stable.inplace(arr) === arr  // => true

A comparator function can be specified:

// Regular sort() compatible comparator, that returns a number.
// This demonstrates the default behavior.
const lexCmp = (a, b) => String(a).localeCompare(b)
stable(['foo', 'bar', 'baz'], lexCmp)  // => ['bar', 'baz', 'foo']

// Boolean comparator. Sorts `b` before `a` if true.
// This demonstrates a simple way to sort numerically.
const greaterThan = (a, b) => a > b
stable([10, 1, 5], greaterThan)  // => [1, 5, 10]

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