Find and return value if Key exist in JavaScript object which also contain array

Question

var OBJ = {
    code: 42,
    item1: [{
        id: 1,
        name: 'foo'
    }, {
        id: 2,
        city: 'NY'
        name: 'bar'
    }],
    thing: [{
        id: 14,
        name: 'foo'
    }, {
        id: 5,
        street: 'E43'
        name: 'pub'
    }]
};

Javascript object(OBJ) I need a method that returns VALUE of KEY I pass as an argument if KEY is not present in OBJ method should return undefined

getKeyValueFromObject(OBJ , 'street') // should return 'E43'
getKeyValueFromObject(OBJ , 'dog') // should return undefined

I tried this(not working)

getKeyValueFromObject(obj: any, search: string) {
    const notFound = {};
    Object.keys(obj).forEach(key => {
      if (key !== null && key !== undefined && !(obj[key] === undefined || obj[key] === null)) {
        if (key === search) {
          return obj[key];
        } else if (obj[key].constructor === {}.constructor) {
          const result = this.getKeyValueFromObject(obj[key], search);
          if (result !== notFound) return result;
        } else if (Array.isArray(obj[key])) {
          obj[key].forEach(element => {
            const result = this.getKeyValueFromObject(element, search);
            if (result !== notFound) return result;
          });

        }
      }
    });
    return {};
  }

This answer from another post looks like may work for you https://stackoverflow.com/a/40604638/11998044 — Gustavo Alfaro, Aug 19 '21 at 20:29

score 0 · Answer 1 · answered Aug 19 '21 at 21:00

Your code was almost working, but the return statements in your forEach code were not working as you expected. Look here: Grab the return value and get out of forEach in JavaScript?. Instead I used a variable resultKey to store a match.

There were some commas missing in your OBJ json, but I think that was not the main problem.

var OBJ = {
    code: 42,
    item1: [{
        id: 1,
        name: 'foo'
    }, {
        id: 2,
        city: 'NY',
        name: 'bar'
    }],
    thing: [{
        id: 14,
        name: "foo"
    }, {
        id: 5,
        street: "E43",
        name: "pub"
    }]
};

function getKeyValueFromObject(obj, search) {
    let resultKey = undefined;
    const notFound = {};
    Object.keys(obj).forEach(key => {
      if (key !== null && key !== undefined && !(obj[key] === undefined || obj[key] === null)) {
        if (key === search) {
          resultKey = obj[key];
        } else if (obj[key].constructor === {}.constructor) {
          const result = this.getKeyValueFromObject(obj[key], search);
          if (result !== notFound) resultKey = result;
        } else if (Array.isArray(obj[key])) {
          obj[key].forEach(element => {
            const result = this.getKeyValueFromObject(element, search);
            if (result !== notFound) resultKey = result;
          });

        }
      }
      return;
    });
    return resultKey;
}
console.log(getKeyValueFromObject(OBJ, "street"));
console.log(getKeyValueFromObject(OBJ , "dog"));

Find and return value if Key exist in JavaScript object which also contain array

1 Answers1