Developing a program that is capable of receiving a list of numerical values

Question

Developing a program that is capable of receiving a list of numerical values

I am attempting to create a function that will take an array of numbers and generate a new array containing only the first and last elements from the input array.

However, I am encountering some challenges in getting the function to work properly with my current code.

let firstLast = [5, 10 ,15 ,20, 25, 30, 40];
                
                firstLast.splice(1, firstLast.length - 2);
                
                console.log(firstLast);

I envision being able to simply pass the array of numbers as a parameter when calling this function.

javascript arrays

Answer 1

Answer №1

This code snippet creates a new array with only the first and last elements extracted from the given array.

It's important to note that using array.splice() is not the correct approach in this scenario since it alters the original array instead of creating a new one. To achieve the desired result, you should manually construct a new array containing the first and last elements directly.

const newArray = [firstLast[0], firstLast[firstLast.length - 1]]

The first element can always be accessed at index 0, while the last element can be found at index length - 1.

Answer 2

This code snippet creates a new array with only the first and last elements extracted from the given array.

It's important to note that using array.splice() is not the correct approach in this scenario since it alters the original array instead of creating a new one. To achieve the desired result, you should manually construct a new array containing the first and last elements directly.

const newArray = [firstLast[0], firstLast[firstLast.length - 1]]

The first element can always be accessed at index 0, while the last element can be found at index length - 1.

Answer 3

Answer №2

To achieve the same functionality in a single line using an anonymous function, you can add checks like this:

var arr = [5, 10 ,15 ,20, 25, 30, 40];

const getFirstLast = arr => arr && arr.length > 1 ? [arr[0], arr[arr.length - 1]] : arr
console.log(getFirstLast(arr));

Alternatively, you can use a regular function like this:

var arr = [5, 10 ,15 ,20, 25, 30, 40];

function getFirstLast(arr) {
  return arr && arr.length > 1
    ? [arr[0], arr[arr.length - 1]]
    : arr 
}

console.log(getFirstLast(arr));

Answer 4

To achieve the same functionality in a single line using an anonymous function, you can add checks like this:

var arr = [5, 10 ,15 ,20, 25, 30, 40];

const getFirstLast = arr => arr && arr.length > 1 ? [arr[0], arr[arr.length - 1]] : arr
console.log(getFirstLast(arr));

Alternatively, you can use a regular function like this:

var arr = [5, 10 ,15 ,20, 25, 30, 40];

function getFirstLast(arr) {
  return arr && arr.length > 1
    ? [arr[0], arr[arr.length - 1]]
    : arr 
}

console.log(getFirstLast(arr));

Answer 5

Answer №3

When using splice, the original array is mutated. To avoid this, a simple solution is to create a function that only requires the first and last values of the array

var numbers = [5, 10 ,15 ,20, 25, 30, 40];

const getFirstAndLast = (arr) => {
  return Array.isArray(arr) && arr.length > 1 ? [arr[0], arr[arr.length-1]] : arr
}

console.log(getFirstAndLast(numbers));
console.log(getFirstAndLast([1]));
console.log(getFirstAndLast([1,2,3]));
console.log(getFirstAndLast());

Answer 6

When using splice, the original array is mutated. To avoid this, a simple solution is to create a function that only requires the first and last values of the array

var numbers = [5, 10 ,15 ,20, 25, 30, 40];

const getFirstAndLast = (arr) => {
  return Array.isArray(arr) && arr.length > 1 ? [arr[0], arr[arr.length-1]] : arr
}

console.log(getFirstAndLast(numbers));
console.log(getFirstAndLast([1]));
console.log(getFirstAndLast([1,2,3]));
console.log(getFirstAndLast());

Developing a program that is capable of receiving a list of numerical values

Answer №1

Answer №2

Answer №3

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