Before I became familiar with all the built in methods available in Javascript, everything seemed possible with for loops and if statements.

“If you only have a hammer, everything looks like a nail”.

It wasn’t until I started to make the conscious effort to remember string and array methods that things became much easier.

I found some old code that looked something like this.

const userArray = ['London', 'Sydney', 'Madrid', 'Boston', 'Verona', 'Rome', 'Athens', 'Porto', 'Meteora']

let result = []

for(let i = 0; i < 5; i++){
    result.push(userArray[i])
}

console.log(result)
// [ 'London', 'Sydney', 'Madrid', 'Boston', 'Verona' ]

I regularly catch myself defaulting to code like this, but nowadays it triggers a “Is there a simpler version or a method for this problem?”

Let’s use Array.slice(), it doesn’t mutate the original array and personally feels easier to reason about when looking at somebody else’s code.

const userArray = ['London', 'Sydney', 'Madrid', 'Boston', 'Verona', 'Rome', 'Athens', 'Porto', 'Meteora']

let result = userArray.slice(0, 3)

console.log(result)
// [ 'London', 'Sydney', 'Madrid' ]

We can pass in the index to start from and the index to end. Important to remember that the final index item is not included in the slice.

Passing in a number that is greater than the length of the array returns the entire array, so some people may need to add a check before using this.