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javascriptnode.jsecmascript-5

How to search for a key in an object's prototype?

I have an Object which has Objects inside it like this:

obj = {
foo:{x},
bar:{y},

}

i want to search for a key in the sub-objects prototype i.e bar in this context

i have tried this so far without success

for(x in obj){
    if(Object.keys(x.prototype).includes("key_to_be_searched")){
       console.log("true")
}
}

even logging x.prototype returns empty arrays

i am a newbie, so i would really appreciate in-depth explanation or resources where i can learn more about prototypes.

Solution

  • You can check recursively:

    const obj = {
  foo: { x: 'x' },
  bar: { y: 'y' },
}

const checkObjectProp = (o, p) => Object
  .keys(o)
  .some(k => k === p || (typeof o[k] === 'object' && checkObjectProp(o[k], p)))

// Test
const arr = ['foo', 'y', 'asdfasdf']
arr.forEach(p => console.log(checkObjectProp(obj, p)))