foreach key value javascript

Mastering the forEach with Key Value Iteration in JavaScript

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Explore the full potential of for each or forEach method with this easy guide on mastering key value iteration in JavaScript.

Learn how key-value pairs work in JavaScript objects and how to use forEach to work with them effortlessly.

We will provide examples and clear explanations that will help you become a pro at handling key-value pairs in your code.

So without further ado, let’s start learning how to master key-value iteration in JavaScript using the powerful forEach method.

What is key value in JavaScript?

In JavaScript, an object is a collection of key-value pairs, where each key is a string and each value can be any data type.

The keys are used to access the values stored in the object.

An object is a fundamental data structure in JavaScript that allows you to store and organize related data as properties and their corresponding values.

Each property in the object is identified by a unique key, and the associated value represents the data associated with that key.

Here’s an example:

const sampleObject = {
  name: "Itsourcecode",
  age: 18,
  sex: "Male"
};

console.log(sampleObject.name); 
console.log(sampleObject.age); 
console.log(sampleObject.sex);

As you can see, sampleObject is an object with three key-value pairs. The keys are name, age, and sex, and the corresponding values are “Itsourcecode”, 18, and “Male.”

You can access the value associated with a key using dot notation, as shown in the console.log() statements.

Output:

Itsourcecode
18
Male

How to use key value in forEach JavaScript?

In JavaScript, you can use the forEach() method to iterate over the key-value pairs of an object.

The forEach() method is a built-in function of arrays, so you’ll need to convert the object into an array first using Object.entries().

Here’s an example on how to Use forEach() with key value Pairs:

const sampleObject = {
  name: "Itsourcecode",
  age: 18,
  sex: "Male"
};

Object.entries(sampleObject).forEach(([key, value]) => {
  console.log(`Key: ${key}, Value: ${value}`);
});

In this example, sampleObject is an object with three key-value pairs. The keys are name, age, and sex, and the corresponding values are “Itsourcecode”, 18, and “Male.”

The Object.entries() method is used to convert the object into an array of key-value pairs, which is then passed to the forEach() method.

The forEach() method takes a callback function as an argument, which is called for each element in the array.

In this case, the callback function uses destructuring to extract the key and value from each element, and then logs them to the console.

How to check every key value in object JavaScript?

You can use a for…in loop to iterate over the keys of an object and check the value associated with each key in JavaScript.

Here’s an example:

const sampleObject = {
  name: "Itsourcecode",
  age: 18,
  sex: "Male"
};

for (const key in sampleObject) {
  console.log(`Key: ${key}, Value: ${sampleObject[key]}`);
}

In this example, sampleObject is an object with three key-value pairs. The keys are name, age, and sex, and the corresponding values are “Itsourcecode“, 18, and “Male.”

The for…in loop iterates over the keys of the object, and the value associated with each key is accessed using bracket notation (sampleObject[key]). The key and value are then logged to the console.

Output:

Key: name, Value: Itsourcecode
Key: age, Value: 18
Key: sex, Value: Male

How to get values from keys in JavaScript?

You can access or get the values of an object’s keys using either dot notation or bracket notation in JavaScript.

Here’s an example:

const sampleObject = {
name: "Itsourcecode",
age: 18,
sex: "Male"
};

// Using dot notation
console.log(sampleObject.name); 

// Using bracket notation
console.log(sampleObject['age']);

In this example, sampleObject is an object with three key-value pairs. The keys are name, age, and sex, and the corresponding values are “Itsourcecode“, 18, and “Male.”

To get the value associated with a key using either dot notation (sampleObject.name) or bracket notation (sampleObject[‘age’]), as shown in the console.log() statements.

Output:

Itsourcecode
18

Conclusion

In conclusion, this article discusses mastering key-value iteration in JavaScript using the forEach method is a powerful technique for working with objects and their properties.

JavaScript objects are collections of key-value pairs, where each key is a string and each value can be any data type.

The forEach method allows you to iterate over the key-value pairs of an object, providing a convenient way to access and work with the data stored within.

Converting the object into an array using Object.entries() and utilizing the forEach() method with a callback function, you can easily access both the keys and their corresponding values.

We are hoping that this article provides you with enough information that help you understand the foreach with key value in JavaScript.

You can also check out the following article:

Thank you for reading itsourcecoders 😊.


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