I am trying to get the key of a JS Object in Typescript from an input value, the problem is that the values are inside an Array.
This is what I have seen in the case that the value is not in an array:
const exampleObject = {
key1: 'Geeks',
key2: 'Javascript'
};
function getKeyByValue(object, value) {
for (var prop in object) {
if (object.hasOwnProperty(prop)) {
if (object[prop] === value)
return prop;
}
}
}
console.log(getKeyByValue(exampleObject,'Geeks')) // key1
This is an example of my object that I want to get the key from:
const exampleObject = {
key1: ['Geeks','test1','test2'],
key2: ['Javascript','test3','test4']
};
function getKeyByValue(object, value) {
for (var prop in object) {
if (object.hasOwnProperty(prop)) {
if (object[prop] === value)
return prop;
}
}
}
console.log(getKeyByValue(exampleObject,'Geeks')) // undefined
I need to get the key without using Array.prototype.includes(), because typing the resulting variable as String gives me an error that it may be undefined.
My problem: I don't know how to go through the array inside the function to find the value and get the key
Update:
What I want is to avoid the possibility of returning an undefined, since the input value will always be inside the object, how can I achieve this?
@segmet You can use my code
const exampleObject = {
key1: ['Geeks', 'test1', 'test2'],
key2: ['Javascript', 'test3', 'test4']
};
function getKeyByValue(object, value) {
var output = "";
for (var prop in object) {
// finding and removing element from array
object[prop].find(i => {
if (i === value) {
output = prop;
return prop;
}
}
)
}
return output
}
console.log(getKeyByValue(exampleObject, 'Geeks'))
function getKeyByValue(object, value) {
const key = Object.entries(object).filter(([key, val]) => val.includes(value));
return Object.fromEntries(key);
}
Try this function instead You will get the object matching your keys
You can do something like this and then check for null
const getKeyFromValue = (obj:Object, value:string | string[]) => {
for (let key in obj) {
if (typeof value === 'string') {
if (obj[ key ].includes(value)) {
return key;
}
}
else if (Array.isArray(value)) {
if (obj[ key ].every(val => value.includes(val))) {
return key;
}
}
}
return null;
}