Searching for an object in a more efficient manner

Question

Searching for an object in a more efficient manner

At times, I often find myself needing to locate a specific object within an array of objects where the key I am searching for matches a particular value.

For instance:

var cars = [
    { id:23, make:'honda', color: 'green' },
    { id:36, make:'acura', color:'silver' },
    { id:18, make:'ford', color:'blue' },
    { id:62, make:'ford', color:'green' }, 
];

Let's say I want to access the entry with id=18.

Currently, my approach looks like this:

function select(key,val,arr){

    for(var i in arr){
        if(arr[i][key]==val) return(arr[i]);
    }
    return(null); // object not found in arr
}


var id = 18;
var car = select('id', id, cars);

// car = { id:18, make:'ford', color:'blue' }

However, this method feels cumbersome and lacks scalability. Retrieving a value from a large dataset can be quick if it's towards the beginning of the array or could take as many iterations as there are entries. Moreover, it seems inefficient when the desired value does not exist, as you end up iterating through all objects only to yield a null result.

Is there a more streamlined way to search an array or object for a value when the search criteria isn't aligned with the subject's keys?

javascript arrays json object array-algorithms

Answer 1

Answer №1

To optimize your search process, you have two options: using the Array.prototype.map() method to create a shadow array or creating an index object like demonstrated in the code snippet below.

var cars = [
    { id:23, make:'honda', color: 'green' },
    { id:36, make:'acura', color:'silver' },
    { id:18, make:'ford', color:'blue' },
    { id:62, make:'ford', color:'green' }, 
];
let cars_s = cars.map(function(x) {
    return x.id;
});
let i = cars_s.indexOf(18);
console.log(i); // 2
console.log(cars[i]); // { id:18, make:'ford', color:'blue' }

let index = {};
for (let j = 0; j < cars_s.length; j++) {
    index[cars_s[j]] = j;
}
console.log(index[18]); // 2

Answer 2

To optimize your search process, you have two options: using the Array.prototype.map() method to create a shadow array or creating an index object like demonstrated in the code snippet below.

var cars = [
    { id:23, make:'honda', color: 'green' },
    { id:36, make:'acura', color:'silver' },
    { id:18, make:'ford', color:'blue' },
    { id:62, make:'ford', color:'green' }, 
];
let cars_s = cars.map(function(x) {
    return x.id;
});
let i = cars_s.indexOf(18);
console.log(i); // 2
console.log(cars[i]); // { id:18, make:'ford', color:'blue' }

let index = {};
for (let j = 0; j < cars_s.length; j++) {
    index[cars_s[j]] = j;
}
console.log(index[18]); // 2

Answer 3

Answer №2

To simplify searching for specific properties, start by creating an object with keys that correspond to the property you wish to search by:

let carsById = {};
cars.forEach(car => carsById[car.id] = car);

From now on, you can access the desired car using carsById[id].

Remember to update carsById whenever you add a new item to cars. Consider creating a custom class to handle this efficiently.

Answer 4

To simplify searching for specific properties, start by creating an object with keys that correspond to the property you wish to search by:

let carsById = {};
cars.forEach(car => carsById[car.id] = car);

From now on, you can access the desired car using carsById[id].

Remember to update carsById whenever you add a new item to cars. Consider creating a custom class to handle this efficiently.

Answer 5

Answer №3

Create a collection where each identifier represents a unique car entity paired with its corresponding object:

var vehicles = {
    27: { id:27, brand:'toyota', color: 'red' },
    41: { id:41, brand:'chevrolet', color:'black' },
    15: { id:15, brand:'honda', color:'white' },
    73: { id:73, brand:'subaru', color:'blue' }, 
};

This method allows for more efficient retrieval of specific information:

console.log(vehicles[15].brand);

Answer 6

Create a collection where each identifier represents a unique car entity paired with its corresponding object:

var vehicles = {
    27: { id:27, brand:'toyota', color: 'red' },
    41: { id:41, brand:'chevrolet', color:'black' },
    15: { id:15, brand:'honda', color:'white' },
    73: { id:73, brand:'subaru', color:'blue' }, 
};

This method allows for more efficient retrieval of specific information:

console.log(vehicles[15].brand);

Searching for an object in a more efficient manner

Answer №1

Answer №2

Answer №3

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