Find a value in a JavaScript object

Question

I have a javascript object which looks like this:

tabAndFieldLink: {
 'key1': ['value11', 'value12', 'value13', 'value14', 'value15'],
 'key2': ['value21', 'value22', 'value23', 'value24', 'value25', 'value26', 'value27'],
 'key3': ['value31', 'value32', 'value33', 'value34'],
 'key4': ['value41', 'value42'],
}

What I want

I have the value value22 and I want to get it's key i.e. key2.

What I tried

for (err in errorArray) {
 //err contain the value i.e. value22
 var resultObject = search(err, tabAndFieldLink);
 console.log("The result is :", resultObject);
}
function search(nameKey, myArray) {
 for (var i = 0; i < myArray.length; i++) {
 if (myArray[i].indexOf(nameKey) !== -1) {
 return myArray[i];
 }
 }
}

But it is printing "The result is :", undefined. How can I get the key?

Thanks.

Answer 1

You should use for...in statement to iterates over the enumerable properties of object tabAndFieldLink and as you need key return it.

for (key in obj) {
 if (obj[key].indexOf(nameKey) !== -1) {
 return key;
 }
}

var tabAndFieldLink = {
 'key1': ['value11', 'value12', 'value13', 'value14', 'value15'],
 'key2': ['value21', 'value22', 'value23', 'value24', 'value25', 'value26', 'value27'],
 'key3': ['value31', 'value32', 'value33', 'value34'],
 'key4': ['value41', 'value42'],
}
//err contain the value i.e. value22
var err = 'value22';
var resultObject = search(err, tabAndFieldLink);
console.log("The result is :", resultObject);
function search(nameKey, obj) {
 for (key in obj) {
 if (obj[key].indexOf(nameKey) !== -1) {
 return key;
 }
 }
}

Answer 2

There are many inbuilt functional behavior present in the Javascript, which can be used in cases like this.

Here is the code using arrays filter

var tabAndFieldLink = {
 'key1': ['value11', 'value12', 'value13', 'value14', 'value15'],
 'key2': ['value21', 'value22', 'value23', 'value24', 'value25', 'value26', 'value27'],
 'key3': ['value31', 'value32', 'value33', 'value34'],
 'key4': ['value41', 'value42'],
}
function getKey(checkValue) {
 for (key in tabAndFieldLink) {
 var newArr = tabAndFieldLink[key].filter(function(value){
 return value == 'value22';
 });
 if(newArr.length > 0) {
 console.log("Found......", key);
 return key;
 }
 }
}
console.log(getKey('value22'));

Answer 3

You could use find and Object Keys function

var data = {
 'key1': ['value11', 'value22', 'value13', 'value14', 'value15'],
 'key2': ['value21', 'value22', 'value23', 'value24', 'value25', 'value26', 'value27'],
 'key3': ['value31', 'value32', 'value33', 'value34'],
 'key4': ['value41', 'value42'],
}
function findValue(search){
var result = []
Object.keys(data).forEach(function(key){
 var r = data[key].find(function(value){ 
 return value === search 
 })
 r && result.push(key)
})
console.log(result)
}
findValue("value22")

Answer 4

You could check with Array#some, if the value is in the array with a specific key, then return that key.

function getKey(object, value) {
 var key;
 Object.keys(object).some(function (k) {
 if (object[k].indexOf(value) !== -1) {
 key = k;
 return true;
 }
 });
 return key;
}
var object = { key1: ['value11', 'value12', 'value13', 'value14', 'value15'], key2: [ 'value21', 'value22', 'value23', 'value24', 'value25', 'value26', 'value27'], key3: ['value31', 'value32', 'value33', 'value34'], key4: ['value41', 'value42'] },
 find = 'value22',
 key = getKey(object, find);
console.log(key);

ES6 with Array#find and Array#includes

function getKey(object, value) {
 return Object.keys(object).find(k => object[k].includes(value));
}
var object = { key1: ['value11', 'value12', 'value13', 'value14', 'value15'], key2: [ 'value21', 'value22', 'value23', 'value24', 'value25', 'value26', 'value27'], key3: ['value31', 'value32', 'value33', 'value34'], key4: ['value41', 'value42'] },
 find = 'value22',
 key = getKey(object, find);
console.log(key);

Answer 5

The tabAndFieldLink structure is a Hash containing key value pairs. Each value is an Array.

Navigate the structure as per the snippet below.

var tabAndFieldLink = {
 'key1': ['value11', 'value12', 'value13', 'value14', 'value15'],
 'key2': ['value21', 'value22', 'value23', 'value24', 'value25', 'value26', 'value27'],
 'key3': ['value31', 'value32', 'value33', 'value34'],
 'key4': ['value41', 'value42'],
};
var resultObject = search("value22", tabAndFieldLink);
console.log("The result is :", resultObject);
function search(nameKey, myHash) {
 for (var key in myHash) {
 if (myHash[key].indexOf(nameKey) !== -1) {
 return key;
 }
 }
}