in-place

Fast, low-garbage functions for manipulating arrays in-place.

$ npm install in-place

var inPlace = require('in-place');

Methods

All these methods directly modify the array you pass in. They never allocate new arrays.

map(array, callback[, thisArg])

Alternative to array.map(callback[, thisArg]).

var array = [1, 2, 3, 4, 5];
 
inPlace.map(array, function (item) { return item * 2 });
 
console.log(array); // [2, 4, 6, 8, 10]

filter(array, callback[, thisArg])

Alternative to array.filter(callback[, thisArg]).

var array = [1, 12.1, 5.2, 22, 6];
 
inPlace.filter(array, function (item) { return item < 10 });
 
console.log(array); // [1, 5.2, 6]

deleteIndex(array, index)

• Very fast method to delete a single item by index.
• Does not preserve the original order.
• If you care about keeping the array in order, use array.splice(index, 1).

var foo = [1, 2, 3, 4, 5, 6, 7];
 
inPlace.deleteIndex(array, 2);
 
console.log(array); // [1, 2, 7, 4, 5, 6]

dedupe(array)

• Removes any repeated items (using === for comparison) from the array.
• The last of each set of duplicate values is retained.

var array = [1, 2, 2, 5, 1, 6, 2];
 
inPlace.dedupe(array);
 
console.log(array); // [5, 1, 6, 2];

dedupeSorted(array)

• Like inPlace.dedupe(array) but faster – for use when you know the array is already sorted (i.e. array[n] <= array[n + 1]).

var array = [1, 2, 2, 3, 5, 6, 6, 6];
 
inPlace.dedupe(array);
 
console.log(array); // [1, 2, 3, 5, 6]

concat(array, ...values)

Alternative to array.concat(...values).

var array = [1, 2];
 
inPlace.concat(array, [3, 4], 5, 6, [7, 8]);
 
console.log(array); // [1, 2, 3, 4, 5, 6, 7, 8]