Tips for accessing the final iteration in a _.forEach() loop

Question

Tips for accessing the final iteration in a _.forEach() loop

Recently I started using lodash and encountered a simple challenge while working with it. I'm currently utilizing a _.forEach() loop in typescript to apply a function to objects within an Array. However, I need to determine when the loop reaches its last iteration in order to execute a specific task.

_.forEach(this.collectionArray, function(value: CreateCollectionMapDto) {
      // perform tasks
      // check for last iteration and execute action
    });

I searched through the documentation but couldn't find any information regarding index. I would appreciate any assistance on this matter. Thank you.

typescript lodash

Answer 1

Answer №1

Hey maybe you could give this a shot:

const arr = ['a', 'b', 'c', 'd'];
arr.forEach((element, index, array) => {
    if (index === (array.length -1)) {
        // This is the last one.
        console.log(element);
    }
});

It's recommended to utilize native functions whenever possible and resort to lodash for more intricate scenarios.

However, using lodash, you can also achieve the same result like this:

const _ = require('lodash');

const arr = ['a', 'b', 'c'];
_.forEach(arr, (element, index, array) => {
    if (index === (array.length -1)) {
        // last one
        console.log(element);
    }
});

Answer 2

Hey maybe you could give this a shot:

const arr = ['a', 'b', 'c', 'd'];
arr.forEach((element, index, array) => {
    if (index === (array.length -1)) {
        // This is the last one.
        console.log(element);
    }
});

It's recommended to utilize native functions whenever possible and resort to lodash for more intricate scenarios.

However, using lodash, you can also achieve the same result like this:

const _ = require('lodash');

const arr = ['a', 'b', 'c'];
_.forEach(arr, (element, index, array) => {
    if (index === (array.length -1)) {
        // last one
        console.log(element);
    }
});

Answer 3

Answer №2

The second argument in the forEach callback function represents the position of the element within the array.

let numbers = [10, 20, 30, 40, 50];

numbers.forEach((num, idx) => {
  if (idx === numbers.length - 1) {
    console.log(num);
  }
})

Answer 4

The second argument in the forEach callback function represents the position of the element within the array.

let numbers = [10, 20, 30, 40, 50];

numbers.forEach((num, idx) => {
  if (idx === numbers.length - 1) {
    console.log(num);
  }
})

Tips for accessing the final iteration in a _.forEach() loop

Answer №1

Answer №2

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