How can I push a prop and its value to objects that don't have that specific property knowing t-CodePudding

what I want to achieve is:-

Loop through the peopleData array, add a prop call it 'age' and give it a value of '-' if one of the objects (array elements) does not have the key 'age'

const peopleData = [
  { name: "Ann", age: 15, email: "[email protected]", birthMonth: "Jan" },
  { name: "Bob", age: 19, email: "[email protected]", birthMonth: "Mar" },
  { name: "Cam", age: 18, email: "[email protected]", birthMonth: "Feb" },
  { name: "Dan" },
  { name: "Steve", birthMonth: "Jun" },
  { name: "Tyson", age: 20, birthMonth: "Dec" },
];

That what I tried to do and it did not work

const addAgeObj = {age: '-'}

const myArr = peopleData.map(personData=> {
  if(!personData.age) {
  peopleData.push(addAgeObj);
  console.log(peopleData);
}
});

CodePudding user response：

peopleData.push is wrong. You need to update the object, not to add new objects to the array.

const peopleData = [
  { name: "Ann", age: 15, email: "[email protected]", birthMonth: "Jan" },
  { name: "Bob", age: 19, email: "[email protected]", birthMonth: "Mar" },
  { name: "Cam", age: 18, email: "[email protected]", birthMonth: "Feb" },
  { name: "Dan" },
  { name: "Steve", birthMonth: "Jun" },
  { name: "Tyson", age: 20, birthMonth: "Dec" },
];

const myArr = peopleData.map(personData=> {
  return {...personData, age: personData.age || '-'}
});

console.log(myArr);

CodePudding user response：

const addAgeObj = {age: '-'}
const peopleData = [
    { name: "Ann", age: 15, email: "[email protected]", birthMonth: "Jan" },
    { name: "Bob", age: 19, email: "[email protected]", birthMonth: "Mar" },
    { name: "Cam", age: 18, email: "[email protected]", birthMonth: "Feb" },
    { name: "Dan" },
    { name: "Steve", birthMonth: "Jun" },
    { name: "Tyson", age: 20, birthMonth: "Dec" },
];
const myArr = peopleData.map(personData=> {
    /* if(!personData.age) {
    peopleData.push(addAgeObj);
    console.log(peopleData); 
    }*/
    if(!Object.keys(personData).includes("age"))
        personData={...personData,addAgeObj}
    return personData
});
console.log(myArr)

Try this

CodePudding user response：

peopleData.push does is adding new object and override the existing object.So that is wrong and that is not what you want.so try this one.

const peopleData = [
  { name: "Ann", age: 15, email: "[email protected]", birthMonth: "Jan" },
  { name: "Bob", age: 19, email: "[email protected]", birthMonth: "Mar" },
  { name: "Cam", age: 18, email: "[email protected]", birthMonth: "Feb" },
  { name: "Dan" },
  { name: "Steve", birthMonth: "Jun" },
  { name: "Tyson", age: 20, birthMonth: "Dec" },
];


const myArr = peopleData.map(personData=> {
  if(!personData.age) {
  
 let newobj={...personData,age:"-"};
  
 return newobj;
  
   }
else{

return personData;

  }
});

console.log(myArr);