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Class that allows you to treat multiple arrays as if they were one huge array. Allows merging arrays without creating new copies
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| class MegaArray { | |
| constructor() { | |
| this._arrays = []; | |
| this._size = 0; | |
| } | |
| push(item) { | |
| const array = this._getActiveArray(); | |
| array.push(item); | |
| this._size++; | |
| } | |
| merge(arrayToMerge) { | |
| this._arrays.push(arrayToMerge); | |
| this._size += arrayToMerge.length; | |
| } | |
| forEach(fn) { | |
| let globalIndex = -1; | |
| console.log('Here'); | |
| this._arrays.forEach((array) => { | |
| for (let i = 0; i < array.length; i++) { | |
| globalIndex++; | |
| fn(array[i], globalIndex); | |
| } | |
| }); | |
| } | |
| get(index) { | |
| const [array, localIndex] = this._getArrayLocalIndex(index); | |
| return array[localIndex]; | |
| } | |
| set(index, value) { | |
| const [array, localIndex] = this._getArrayLocalIndex(index); | |
| return array[localIndex] = value; | |
| } | |
| get length() { | |
| return this._size; | |
| } | |
| _getActiveArray() { | |
| if (this._arrays.length == 0) { | |
| this._arrays.push([]); | |
| } | |
| return this._arrays[this._arrays.length - 1]; | |
| } | |
| _getArrayLocalIndex(globalIndex) { | |
| // this can probably be optimized | |
| // TODO: you should perform error-checking to ensure | |
| // index is not out of bounds | |
| let itemsSeen = 0 | |
| let array; | |
| let offset = 0; | |
| for (let a = 0; a < this._arrays.length; a++) { | |
| offset = itemsSeen; | |
| itemsSeen += this._arrays[a].length; | |
| if (itemsSeen > globalIndex) { | |
| array = this._arrays[a]; | |
| break; | |
| } | |
| } | |
| const localIndex = globalIndex - offset; | |
| return [array, localIndex]; | |
| } | |
| } | |
| const array = new MegaArray(); | |
| array.push(10); | |
| array.push(20); | |
| array.merge([1, 2, 3, 4]); | |
| array.set(3, 15); | |
| array.push(45); | |
| array.merge([67, 89]); | |
| console.log("Length", array.length); | |
| console.log("Item at index 4", array.get(4)); | |
| console.log("Print all items"); | |
| array.forEach((item, index) => | |
| console.log("Element at ", index, "is", item)); | |
| // Should print 10, 20, 1, 15, 3, 4, 45, 67, 89 |
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Iyo
_getArrayLocalIndexinado nini