I'm aware this question has been asked many times but I can't find the solution to my specific problem. I'm guessing that I need to refactor my code entirely but could use some guidance.
I am practicing OOP in Javascript. I would like to join an array and add an "and" conjunction before the last element. That way [1, 2, 3] ==> "1, 2, and 3".
I have included my code with comments below. As you will see, the current output I'm getting is "1, 2, and, 3". How can I get rid of the extra comma? Am I going about this the wrong way?
class Person {
constructor(first, last, age, gender, interests) {
this.name = {
first: first,
last: last,
};
this.age = age;
this.gender = gender;
this.interests = interests;
}
greeting() {
console.log(`Hi! I'm ${this.name.first} ${this.name.last}.`)
}
bio() {
// store the index of the last element of the array in a variable called index
let index = this.interests.length - 1;
// store the conjunction for end of array
let conjunction = " and"
// insert the conjunction before last element in array
this.interests.splice(index, 0, conjunction)
// join the array into a string separated by commas
let interestsString = this.interests.join(", ");
console.log(interestsString);
}
}
let person1 = new Person('test', 'test', '29', 'Male', ['skiing', 'cooking', 'gardening']);
console.log(person1.bio());Use Intl.ListFormat() to convert the list to a string while handling the separator, and the conjunction:
const listFormatter = new Intl.ListFormat('en', { style: 'long', type: 'conjunction' });
class Person {
constructor(first, last, age, gender, interests) {
this.name = {
first: first,
last: last,
};
this.age = age;
this.gender = gender;
this.interests = interests;
}
greeting() {
console.log(`Hi! I'm ${this.name.first} ${this.name.last}.`)
}
bio() {
return listFormatter.format(this.interests);
}
}
let person1 = new Person('test', 'test', '29', 'Male', ['skiing', 'cooking', 'gardening']);
console.log(person1.bio());Another option is to use array manipulation - if the array contains only a single item, return that item. If the it contains more than one item, create a new array with all the original items, but the last, and the last item back after adding "and" to it. Join the array.
class Person {
constructor(first, last, age, gender, interests) {
this.name = {
first: first,
last: last,
};
this.age = age;
this.gender = gender;
this.interests = interests;
}
greeting() {
console.log(`Hi! I'm ${this.name.first} ${this.name.last}.`)
}
bio() {
return this.interests.length > 1 // if there are multiple items
?
[
...this.interests.slice(0, -1), // get all items but the last
`and ${this.interests.at(-1)}` // add the last item with "and"
].join(', ') // join
:
this.interests.at(0); // just take the single existing item
}
}
let person1 = new Person('test', 'test', '29', 'Male', ['skiing', 'cooking', 'gardening']);
console.log(person1.bio());Here's one way of doing what you need.
class Person {
constructor(first, last, age, gender, interests) {
this.name = {
first: first,
last: last,
};
this.age = age;
this.gender = gender;
this.interests = interests;
}
greeting() {
console.log(`Hi! I'm ${this.name.first} ${this.name.last}.`)
}
bio() {
let interestsString = this.interests.join(', ').replace(/, ([^,]*)$/, ' and $1')
console.log(interestsString);
}
}
let person1 = new Person('test', 'test', '29', 'Male', ['skiing', 'cooking', 'gardening']);
console.log(person1.bio());when you used splice like this
this.interests.splice(index, 0, conjunction)
you add element to the array , then the join function added another "," better to just change the element it self and adding the and to it.
like this:
let changeTo = conjunction + this.interests[index];
this.interests.splice(index, 1, changeTo);