@apicart/js-utils/src/components/Loops.ts

A small set of useful utilities for easier development

class Loops {

	public forEach(iterable: any | null, callback: Function): this
	{
		let iterator: number;
		const iteratorObject = {
			iterableLength: 0,
			counter: 0,
			isEven: function (): boolean {
				return this.counter % 2 === 0;
			},
			isOdd: function (): boolean {
				return Math.abs(this.counter % 2) === 1;
			},
			isFirst: function (): boolean {
				return this.counter === 1;
			},
			isLast: function (): boolean {
				return this.counter === this.iterableLength;
			}
		};
		let iterableLength: number;
		let statement: boolean;
		let keys: string[];
		let keysLength: number;
		let key: string|number;

		if (iterable === null || ['undefined', 'number'].includes(typeof iterable)) {
			return;
		}

		if (Array.isArray(iterable)) {
			iterableLength = Object.keys(iterable).length;

			if (!iterableLength) {
				return;
			}

			iteratorObject.iterableLength = iterableLength;
			for (iterator = 0; iterator < iterableLength; iterator++) {
				iteratorObject.counter++;
				statement = callback.apply(iteratorObject, [iterable[iterator], iterator]);

				if (statement === false) {
					break;
				}
			}

		} else {
			keys = Object.keys(iterable);
			keysLength = keys.length;

			if (!keys.length) {
				return;
			}

			iteratorObject.iterableLength = keysLength;
			for (iterator = 0; iterator < keysLength; iterator++) {
				iteratorObject.counter++;
				key = keys[iterator];
				statement = callback.apply(iteratorObject, [iterable[key], key]);

				if (statement === false) {
					break;
				}
			}
		}

		return this;
	}

}
export default new Loops();