Best way to compare an array of strings to an array objects with string properties?

问题

I have an array of object, within those objects is a name property.

const objArr = [ { name: "Avram" }, { name: "Andy" } ];

I’m collecting an array of strings from an outside source containing names.

const strArr = [ "Avram", "Andy", "Brandon" ];

If strArr contains a string that does not exist as a property name on an object in objArr, I need to create a new object and push it to objArr.

For example: objArr.push( { name: "Brandon" } );

Obviously, I can use nested loops, but I’d like to avoid that if possible. What is the best way to do this programmatically?

回答1:

like this

const objArr = [ { name: "Avram" }, { name: "Andy" } ];

const strArr = [ "Avram",  "Andy",  "Brandon" ];

const names= objArr.map(x => x.name);

strArr.forEach(str => {
  if (! names.includes(str) ) {
    objArr.push({name: str});
  }
});

console.log(objArr);

回答2:

function fillMissing(arr, names) {
  names.forEach(name => {                         // for each name in names
    if(arr.every(obj => obj.name !== name)) {     // if every object obj in the array arr has a name diferent than this name (this name doesn't exist in arr)
      arr.push({name});                           // then add an object with that name to arr
    }
  });
}

const objArr = [ { name: "Avram" }, { name: "Andy" } ];
const strArr = [ "Avram",  "Andy",  "Brandon" ];

fillMissing(objArr, strArr);
console.log(objArr);

回答3:

Map objArr to same structure as strArr. Then concat the 2 arrays. Run it through a Set to remove duplicates, then remap to correct array of object

const objArr = [ { name: "Avram" }, { name: "Andy" }, { name: "John"} ];

const strArr = [ "Avram",  "Andy",  "Brandon" ];

const res = Array.from(new Set(objArr.map(i=>i.name).concat(strArr))).map(i=>({name:i}))
console.log(res);

回答4:

const objArr = [ { name: "Avram" }, { name: "Andy" } ];
const strArr = [ "Avram",  "Andy",  "Brandon" ];

const objNamesArr = objArr.map((obj) => obj.name)

strArr.forEach((ele) => objNamesArr.indexOf(ele) == -1 && objArr.push({name:ele}))
console.log('objArr', objArr);
console.log('strArr', strArr);

来源：https://stackoverflow.com/questions/47465037/best-way-to-compare-an-array-of-strings-to-an-array-objects-with-string-properti

标签

javascript

arrays

performance

properties

nested-loops