Consider the following example with dynamic arrays:
let numbersArray = [];
for(let i = 0; i < 5; i++)
numbersArray.push(i+1);
and then we have another array:
let valuesArray = Array(6); //Keep in mind that this array has a size of 6 compared to the initial array which had a size of 5.
for(let i = 0; i < 5; i++)
valuesArray[i] = i+1;
Now, the operation to append an element to the end of the array is demonstrated with:
numbersArray.push(6);
There's a question raised regarding whether this operation will have a complexity of O(n), involving moving the array to a new one before appending 6, or if it will simply be O(1).
Furthermore, a comparison is made between declaring an empty array like const numbersArray = [] and populating it versus initializing an empty array (with a known size) and filling it with elements individually.
Let's illustrate this comparison through two methods:
Method 1:
const firstArray = [];
for(let i = 0; i < 5; i++)
firstArray.push(retrieveFirstFiveValues(i));
//Assuming retrieveFirstFiveValues is a separate function
firstArray.push(getSixthValue());
or Method 2:
const secondArray = Array(6);
for(let i = 0; i < 5; i++)
secondArray[i] = retrieveFirstFiveValues(i);
secondArray[secondArray.length - 1] = getSixthValue();