Tech Talk

How would you remove duplicate members from an array?
Input: [1, 1, 3, 5, 8, 7, 3, 8, 99]
Output: [1,5,7,3,8,99]

This can also be done in a similar way creating nested loop. Check each number’s existence and keep a counter, if the counter is equal to 0, then add that number into a new array. This solution can be implemented in any language and also using while, do while loops as well.

Javascript:

			let arrayWithDuplicates  = [1, 1, 3, 5, 8, 7, 3, 8, 99];
			let arrayLengthWithDuplicates = arrayWithDuplicates.length;
			let arrayWithUniqueValues = [];
			let counter = 0;

			for (i = 0; i < arrayLengthWithDuplicates; i++) {
				counter = 0;

				for (j = i + 1; j < arrayLengthWithDuplicates; j++) {
					if (arrayWithDuplicates[i] === arrayWithDuplicates[j]) {
						counter++;
					}
				}

				if (counter === 0) {
					arrayWithUniqueValues.push(arrayWithDuplicates[i]);
				}
			}

			console.log('With duplicate values : ' + arrayWithDuplicates);
			console.log('With unique values : ' + arrayWithUniqueValues);
									

One of my favorite npm module is lodash. This whole loop written above can be done in one line using uniq function of lodash.

		const _ = require(‘lodash’);
		let arrayWithDuplicates  = [1, 1, 3, 5, 8, 7, 3, 8, 99];
		let arrayWithUniqueValues = _.uniq(arrayWithDuplicates);

		console.log('With duplicate values : ' + arrayWithDuplicates);
		console.log('With unique values using lodash : ' + arrayWithUniqueValues);