Kevin Powell - Community•2y ago

modifying Array and outputting the modified version

I want to output all the arrays with modified version, I want to put ? in the end of usernames and ! in the end of items

const array = [
  {
    username: "john",
    team: "red",
    score: 5,
    items: ["ball", "book", "pen"]
  },
  {
    username: "becky",
    team: "blue",
    score: 10,
    items: ["tape", "backpack", "pen"]
  },
  {
    username: "susy",
    team: "red",
    score: 55,
    items: ["ball", "eraser", "pen"]
  },
  {
    username: "tyson",
    team: "green",
    score: 1,
    items: ["book", "pen"]
  },

];


Solution:

const nArray3 = array.map(user => {
  user.username = user.username.map(uName => {
    return uName + "?";
  })
  
  user.items = user.items.map(item => {
    return item + "!";
  })
  return user;
})

console.log(nArray3);

const array = [
  {
    username: "john",
    team: "red",
    score: 5,
    items: ["ball", "book", "pen"]
  },
  {
    username: "becky",
    team: "blue",
    score: 10,
    items: ["tape", "backpack", "pen"]
  },
  {
    username: "susy",
    team: "red",
    score: 55,
    items: ["ball", "eraser", "pen"]
  },
  {
    username: "tyson",
    team: "green",
    score: 1,
    items: ["book", "pen"]
  },

];


Solution:

const nArray3 = array.map(user => {
  user.username = user.username.map(uName => {
    return uName + "?";
  })
  
  user.items = user.items.map(item => {
    return item + "!";
  })
  return user;
})

console.log(nArray3);

Why does it output user.username.map is not a function?

5 Replies

Jochem•2y ago

.map is a function that exists on arrays, user.username is a string

  user.username = user.username.map(uName => {
    return uName + "?";
  })

  user.username = user.username.map(uName => {
    return uName + "?";
  })

this should be this

  user.username = user.username + "?";

  user.username = user.username + "?";

Or even just this

  user.username += "?";

  user.username += "?";

Dev_zxcOP•2y ago

i thought you have to loop through the username specifically like what i did on looping all through the array

Jochem•2y ago

it's just a string, there's nothing to loop over because it's a single value you technically can loop over a string if you slice it first, but that would add a ? in between every character if your array items looked like this:

  {
    username: ["tyson"],
    team: "green",
    score: 1,
    items: ["book", "pen"]
  },

  {
    username: ["tyson"],
    team: "green",
    score: 1,
    items: ["book", "pen"]
  },

that'd be different, but the way you have it now you cannot loop over the username

Dev_zxcOP•2y ago

oh when i did the map(user) im already in the array, so thats why i cannot loop through the usernames using map, items.map(item) is working because its an array

Jochem•2y ago

well, you can't loop through the usernames using map ever, even if you just access it by using array[0].username, but yes, you're already looping over the users and that's why you have access to the username right away and correct about items.map, that works because it's an array

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modifying Array and outputting the modified version