How to get first N elements of an array in JavaScript
In this tutorial, we’ll look at how to obtain the first N elements from an array in JavaScript. There are a few different ways to obtain N items from an array using JavaScript, but we’ll go through two of them.
- JavaScript Convert 12 Hour AM/PM Time to 24 Hour Time Format
- Remove an element from an array in JavaScript
- How to lowercase or uppercase all array values in JavaScript
- How to truncate a string in JavaScript
1. slice() method
We’ll use the slice() function to obtain the top 5 elements from an array in this method. It’s the most convenient way to obtain stuff.
Example 1: Get the first 5 elements
const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
// get the first 5 elements
const n = 5;
const newArr = arr.splice(0, n);
console.log(newArr);
// [1, 2, 3, 4, 5]
Example 2: Get the first 2 elements
const arr = [
{
userId: 1,
id: 1,
title: "delectus aut autem",
completed: false
},
{
userId: 2,
id: 2,
title: "quis ut nam facilis et officia qui",
completed: false
},
{
userId: 1,
id: 3,
title: "fugiat veniam minus",
completed: false
}
];
const n = 2;
const newArr = arr.splice(0, n);
console.log(newArr);
/*
[
{
userId: 1,
id: 1,
title: "delectus aut autem",
completed: false
},
{
userId: 2,
id: 2,
title: "quis ut nam facilis et officia qui",
completed: false
}
]
*/
2. filter() method
We can also obtain the first N number of entries from the list using the filter() function. To filter the records, we’ll need to use the element index.
Example 1: Get the first 5 elements
const arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
// get the first 5 elements
const n = 5;
const newArr = arr.filter((x, i) => i
Example 2: Get the first 2 elements
const arr = [
{
userId: 1,
id: 1,
title: "delectus aut autem",
completed: false
},
{
userId: 2,
id: 2,
title: "quis ut nam facilis et officia qui",
completed: false
},
{
userId: 1,
id: 3,
title: "fugiat veniam minus",
completed: false
}
];
const n = 2;
const newArr = arr.filter((x, i) => i
That’s it for today.
Thank you for reading. Happy Coding..!!