1.11 - Other list/array functionality

Splitting a string into an array of strings

We split strings the hard way before because we hadn’t learnt about lists, but now we can use the easy method known as the split() function.

let birthday = prompt("Please enter your date of birth as dd/mm/yyyy : ");
let parts = birthday.split("/");
console.log("Your day of birth is ", parts[0]);
console.log("Your month of birth is ", parts[1]);
console.log("Your year of birth is ", parts[2]);

Joining a list together

Just as we can split a string into a list, we can join it back together again too.

let addressList = ["Chemin de la Grangette 2","1052 Le Mont-sur-Lausanne","Switzerland"];
let newAddress = addressList.join(", ");
console.log(newAddress);

Appending an item to a list

let beatlesMembers = ["John", "Paul", "George"]
let beatlesMembers.push("Ringo")

Deleting items from a list based on it’s value

let beatlesMembers = ["John", "Paul", "George", "Ringo"];
console.log(beatlesMembers);

let deleteThis = "Ringo";
let position = beatlesMembers.indexOf( deleteThis );
while (position >= 0) {
    beatlesMembers.splice(position, 1);
    position = beatlesMembers.indexOf( deleteThis );
}

console.log(beatlesMembers);

Delete an item using it’s index number.

let days = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
days.splice(4 ,2);    // will remove 2 items from after the 4th value
console.log(days);    // let's have a 3 day week by deleting Thursdays and Fridays!