JSFiddle - React, Tailwind, and code Playground

JavaScript

const arr = [1,2,3,4,5]
const arr2 = [1,2,3,4,5]
const arr3 = [1,2,3,4,5]

const arrDelLast = (arr) => {
	return arr.filter( (el, i) => i < arr.length - 1) 
}

const arrDelLast2 = (arr) => {
	return arr.splice(-1, 1)
}

const arrDelLast3 = (arr) => {
	return arr.slice(0, -1)
}

console.log('arr ------')
console.log(arrDelLast(arr))
console.log(arr)

console.log('arr2 ------')
console.log(arrDelLast2(arr2))
console.log(arr2)

console.log('arr3 ------')
console.log(arrDelLast3(arr3))
console.log(arr3)