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How to Find Property Values in an Array of Object using if/else Condition in JavaScript ?

Finding property values in an array of objects using if/else condition is particularly useful when there is a collection of objects.

Table of Content

Using Array Find Method

The array find method loop in JavaScript is used to retrieve the first element in an array that satisfies a given condition. In this approach, using the find() method, we create a function findPropertyValue() to filter objects in the ‘objectsArray’ array based on a specific object id, returning an object property value.

Syntax:

array.find(function(currentValue, index, arr), thisValue)

Example: The below code uses the JavaScript array find method to find property values in an array of objects.

JavaScript 
const objectsArray = [
    { id: 1, name: "GeeksforGeeks" },
    { id: 2, name: "Computer Science" },
    { id: 3, name: "Portal" },
    { id: 4, name: "For Geeks" },
    { id: 5, name: "GFG" },
]

const findPropertyValue = (objectId) => {
    const object = 
        objectsArray.find((object) => object.id === objectId);
    if (object) {  //If-else condition
        return object.name;
    }
    else {
        return null;
    }
}

// Prints "name" property value of object with "id" 2
console.log(findPropertyValue(2));

Output
Computer Science

Using Array Filter Method

In this approach, using the filter() method, we create a function findPropertyValue() to filter objects in the ‘objectsArray’ array based on a specific object id, returning an object property value in the form of a new array containing this particular object property that satisfies the specified condition.

Syntax:

array.filter(callback(element, index, arr), thisValue)

Example: The below code uses the JavaScript array filter method to find property values in an array of objects.

JavaScript 
const objectsArray = [
    { id: 1, name: "GeeksforGeeks" },
    { id: 2, name: "Computer Science" },
    { id: 3, name: "Portal" },
    { id: 4, name: "For Geeks" },
    { id: 5, name: "GFG" },
]

function getPropertyValue(objectId) {
    const property = 
        objectsArray.filter(object => object.id == objectId);
    if (property[0].name != null) {  //If-else condition
        return property[0].name;
    }
    else {
        return;
    }

}

//Prints "name" property value of object with "id" 1
console.log(getPropertyValue(1));

Output
GeeksforGeeks

Using For Of Loop

In this approach, we create a function findPropertyValue() using a for-of loop to iterate through objects based on a specific object ID, searching for a property’s value accordingly. The matching object property value is returned as the output.

Example: The below code uses the JavaScript for-of loop to find property values in an array of objects.

JavaScript 
const objectsArray = [
    { id: 1, name: "GeeksforGeeks" },
    { id: 2, name: "Computer Science" },
    { id: 3, name: "Portal" },
    { id: 4, name: "For Geeks" },
    { id: 5, name: "GFG" },
]

function getPropertyValue(objectID) {
    for (const obj of objectsArray) {
        if (obj.id == objectID) {  //If-else condition
            return obj.name;
        } else {
            continue;
        }
    }
    return null;
}

//Prints "name" property value of object with "id" 3
console.log(getPropertyValue(3));

Output
Portal

Using Array Map Method

Another useful approach to find and transform property values in an array of objects is by utilizing the map() method. The map() method creates a new array populated with the results of calling a provided function on every element in the calling array. This can be particularly useful for extracting or transforming specific property values.

Example: In this example, we use the map() method to find and transform property values in an array of objects. The function findAndTransformPropertyValue() takes an array of objects and a specific property name, then returns a new array containing the values of the specified property for each object.

JavaScript 
function findAndTransformPropertyValue(objectsArray, propertyName) {
    return objectsArray.map(obj => obj[propertyName]);
}

const objectsArray = [
    { id: 1, name: 'Alice', age: 25 },
    { id: 2, name: 'Bob', age: 30 },
    { id: 3, name: 'Charlie', age: 35 }
];

const names = findAndTransformPropertyValue(objectsArray, 'name');
console.log(names); // Output: ['Alice', 'Bob', 'Charlie']

const ages = findAndTransformPropertyValue(objectsArray, 'age');
console.log(ages); // Output: [25, 30, 35]

Output
[ 'Alice', 'Bob', 'Charlie' ]
[ 25, 30, 35 ]

Using Array Reduce Method

The reduce method executes a reducer function on each element of the array, resulting in a single output value. This method can be particularly useful for aggregating or accumulating property values based on certain conditions.

Example: The following code demonstrates how to use the JavaScript reduce method to find a property value in an array of objects. We create a function findPropertyValueUsingReduce() that accumulates the desired property value based on a specific object ID.

JavaScript 
const objectsArray = [
    { id: 1, name: "GeeksforGeeks" },
    { id: 2, name: "Computer Science" },
    { id: 3, name: "Portal" },
    { id: 4, name: "For Geeks" },
    { id: 5, name: "GFG" },
];

const findPropertyValueUsingReduce = (objectId) => {
    return objectsArray.reduce((accumulator, currentObject) => {
        if (currentObject.id === objectId) {  // If-else condition
            return currentObject.name;
        }
        return accumulator;
    }, null);
};

// Prints "name" property value of object with "id" 4
console.log(findPropertyValueUsingReduce(4));

Output
For Geeks

Using Array Some Method

The some method tests whether at least one element in the array passes the provided test function. This can be useful for finding a property value and stopping the search as soon as the condition is met.

Example: The following code demonstrates how to use the JavaScript some method to find a property value in an array of objects. We create a function findPropertyValueUsingSome() that returns the property value of an object based on a specific object ID if it exists.

JavaScript 
const objectsArray = [
    { id: 1, name: "GeeksforGeeks" },
    { id: 2, name: "Computer Science" },
    { id: 3, name: "Portal" },
    { id: 4, name: "For Geeks" },
    { id: 5, name: "GFG" },
];

const findPropertyValueUsingSome = (objectId) => {
    let result = null;
    objectsArray.some(object => {
        if (object.id === objectId) {  // If-else condition
            result = object.name;
            return true;
        }
        return false;
    });
    return result;
};
console.log(findPropertyValueUsingSome(5));

Output
GFG




Reffered: https://www.geeksforgeeks.org

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Category:
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Sub Category:
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