Generate Key Value Pairs In An Object

  
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  • 1 day ago  The Object.entries method in JavaScript returns an array consisting of enumerable property key, value pairs of the object. The only difference is that the Object.keys method returns only the own property names and it only works for ES5 while Object.entries method returns an array of arrays with key and value and it works from ES6.
  • Create key-value pairs string in JSON. Json Object - Getting the Key and the Value. Returning string representation of key value pairs in JSONArray-2.
  • Nov 16, 2018 3. Key-value pair Generation in MapReduce. Let us now learn how key-value pair is generated in Hadoop MapReduce?In MapReduce process, before passing the data to the mapper, data should be first converted into key-value pairs as mapper only understands key-value pairs of data.
  • Adding by obj'key' or obj.key are all solid pure JavaScript answers. However both of LoDash and Underscore libraries do provide many additional convenient functions when working with Objects and Arrays in general.push is for Arrays, not for objects. Depending what you are looking for.

Create Key Value Pair Array Using Javascript, Our today's article is simple but demanding. Most of the new or experience java-script developer required below code. In this code snippet I have define java-script array values are in the form of key and value.

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An object is an instance which contains set of key value pairs. The values can be scalar values or functions or even array of other objects. The syntax is given below −

Syntax

As shown above, an object can contain scalar values, functions and structures like arrays and tuples.

Example: Object Literal Notation

On compiling, it will generate the same code in JavaScript.

The output of the above code is as follows −

TypeScript Type Template

Let’s say you created an object literal in JavaScript as −

In case you want to add some value to an object, JavaScript allows you to make the necessary modification. Suppose we need to add a function to the person object later this is the way you can do this.

If you use the same code in Typescript the compiler gives an error. This is because in Typescript, concrete objects should have a type template. Objects in Typescript must be an instance of a particular type.

You can solve this by using a method template in declaration.

Example: Typescript Type template

On compiling, it will generate the same code in JavaScript.

The output of the above code is as follows −

Objects can also be passed as parameters to function.

Example: Objects as function parameters

The example declares an object literal. The function expression is invoked passing person object.

On compiling, it will generate following JavaScript code.

Its output is as follows −

Generate Key Value Pairs In An Objective

You can create and pass an anonymous object on the fly.

Example: Anonymous Object

On compiling, it will generate following JavaScript code.

Its output is as follows −

Duck-typing

Generate Key Value Pairs In An Object Formula

In duck-typing, two objects are considered to be of the same type if both share the same set of properties. Duck-typing verifies the presence of certain properties in the objects, rather than their actual type, to check their suitability. The concept is generally explained by the following phrase −

“When I see a bird that walks like a duck and swims like a duck and quacks like a duck, I call that bird a duck.”

Generate Key Value Pairs In An Object Chart

The TypeScript compiler implements the duck-typing system that allows object creation on the fly while keeping type safety. The following example shows how we can pass objects that don’t explicitly implement an interface but contain all of the required members to a function.

Javascript Object Key Value

Example