JS Small tricks for Problem solving 1 - Iterating

Iteration in Array, Set, Map

Iterating through an array with an index is pretty straightforward. You can use the ES6 forEach() method:

arr.forEach((item, index) => { ... });

However, when you want to return a value immediately while iterating through an object, it's not easy to exit the parent function.

In such cases, if we are willing to sacrifice a bit of time and space complexity, we can try Object.entries(). After that, we simply use for...of to iterate.

for (let [index, value] of iterable) {
  console.log(index, value);
}

We also use Map and Set in problem-solving to decrease time complexity.

Therefore, we need to be proficient with for...in and for...of for iterating over objects.

In Practice

For example, when you want to find numbers in an array without duplication and then iterate over the array, you can put all numbers into a Set and iterate over it using for...of. That’s it!