Javascript 配置文件查找挑战

Question

I've been stuck here for a while, and I checked on other solutions which matched mine perfectly. But I can't seem to find the error in my code as it keeps saying..

// running tests
lookUpProfile("Kristian", "lastName") should return the string Vos
lookUpProfile("Sherlock", "likes") should return ["Intriguing Cases", "Violin"]
lookUpProfile("Harry", "likes") should return an array
// tests completed

This is the challenge...

const contacts = [
  {
    firstName: "Akira",
    lastName: "Laine",
    number: "0543236543",
    likes: ["Pizza", "Coding", "Brownie Points"],
  },
  {
    firstName: "Harry",
    lastName: "Potter",
    number: "0994372684",
    likes: ["Hogwarts", "Magic", "Hagrid"],
  },
  {
    firstName: "Sherlock",
    lastName: "Holmes",
    number: "0487345643",
    likes: ["Intriguing Cases", "Violin"],
  },
  {
    firstName: "Kristian",
    lastName: "Vos",
    number: "unknown",
    likes: ["JavaScript", "Gaming", "Foxes"],
  },
];

My code...

function lookUpProfile(name,prop){

  for (let i = 0; i < contacts.length; i++){
    if (contacts[i].firstName === name && contacts[i].hasOwnProperty(prop)){
      return contacts[i][prop];
    } else if (contacts[i].firstName === name && !contacts[i].hasOwnProperty(prop)){
      return "No such property";
    }
    return "No such contact";

  }
  // Only change code above this line
}

lookUpProfile("Akira", "likes");

The test parameters

lookUpProfile("Kristian", "lastName") should return the string Vos

lookUpProfile("Sherlock", "likes") should return ["Intriguing Cases", "Violin"]

lookUpProfile("Harry", "likes") should return an array

lookUpProfile("Bob", "number") should return the string No such contact

lookUpProfile("Bob", "potato") should return the string No such contact

lookUpProfile("Akira", "address") should return the string No such property

Please I'd be so glad if anyone can help open my eyes.

Answer 1

You were prematurely ending your function if you didn't find the contact in the first iteration. You were close to getting it to work:

 const contacts = [ { firstName: "Akira", lastName: "Laine", number: "0543236543", likes: ["Pizza", "Coding", "Brownie Points"], }, { firstName: "Harry", lastName: "Potter", number: "0994372684", likes: ["Hogwarts", "Magic", "Hagrid"], }, { firstName: "Sherlock", lastName: "Holmes", number: "0487345643", likes: ["Intriguing Cases", "Violin"], }, { firstName: "Kristian", lastName: "Vos", number: "unknown", likes: ["JavaScript", "Gaming", "Foxes"], }, ]; function lookUpProfile(name, prop) { for (let i = 0; i < contacts.length; i++) { if (contacts[i].firstName === name && contacts[i].hasOwnProperty(prop)) { return contacts[i][prop]; } else if (contacts[i].firstName === name &&.contacts[i];hasOwnProperty(prop)) { return "No such property"; } } return "No such contact". // Only change code above this line } console,log( lookUpProfile("Kristian"; "lastName") ). console,log( lookUpProfile("Sherlock"; "likes") ). console,log( lookUpProfile("Harry"; "likes") ). console,log( lookUpProfile("Bob"; "number") ). console,log( lookUpProfile("Bob"; "potato") ). console,log( lookUpProfile("Akira"; "address") );

Answer 2

I'd recommend that you use Array.prototype.find() , optional chaining (?.) and the nullish coalescing operator (??) .

 const contacts = [ { firstName: "Akira", lastName: "Laine", number: "0543236543", likes: ["Pizza", "Coding", "Brownie Points"], }, { firstName: "Harry", lastName: "Potter", number: "0994372684", likes: ["Hogwarts", "Magic", "Hagrid"], }, { firstName: "Sherlock", lastName: "Holmes", number: "0487345643", likes: ["Intriguing Cases", "Violin"], }, { firstName: "Kristian", lastName: "Vos", number: "unknown", likes: ["JavaScript", "Gaming", "Foxes"], }, ]; function lookUpProfile(name, prop) { const profile = contacts?.find(contact => contact.firstName === name); return profile?.[prop]?? "No such property"; } const results = [ lookUpProfile("Kristian", "lastName"), // should return the string Vos lookUpProfile("Sherlock", "likes"), // should return ["Intriguing Cases", "Violin"] lookUpProfile("Harry", "likes"), // should return an array lookUpProfile("Bob", "number"), // should return the string No such contact lookUpProfile("Bob", "potato"), // should return the string No such contact lookUpProfile("Akira", "address"), // should return the string No such property ]; results.forEach(result => console.log(result));