The Object.assign() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. Objects are assigned and copied by reference. It will return the target object. Show
Syntax:Parametertarget: The target object. sources: The source object(s). Return value:This method returns the target object. Browser Support:ChromeYesEdgeYesFirefoxYesOperaNoExample 1Output: Example 2Output: Example 3Output:
In JavaScript, the 7 data type is used to store key value pairs, and like the 8 data type, contain many useful methods. These are some useful methods you'll use while working with objects.Object Assign MethodThe 9 method is used to
The 9 method requires one 1 as a parameter and can accept an unlimited number of 2 as additional parameters.It's important to note here is that the 1 parameter will always be modified. If that parameter points to an existing object, then that object will be both modified and copied.If, you wish to create a copy of an object without modifying that original object, you can pass an empty object 4 as the first ( 1) parameter and the object to be copied as the second ( 6) parameter.If objects passed as parameters into 9 share the same properties (or keys), property values that come later in the parameters list will overwrite those which came earlier.Syntax
Return Value 9 returns the 1.ExamplesModifying and copying 1:
Copying 1 without modification:
Objects with the same properties:
Object Values MethodThe 2 method takes an object as a parameter and returns an array of its values. This makes it useful for chaining with common 8 methods like 4, 5, and 6.Syntax
Return value An array of the passed object's ( 1) values.Examples
If the object you're passing has numbers as keys, then 8 will return the values according to the numerical order of the keys:
If something other than an object is passed to 2, it will be coerced into an object before being returned as an array:
Object hasOwnProperty MethodThe 0 method returns a boolean indicating if the object owns the specified property.This is a convenient method to check if an object has the specified property or not since it returns true/false accordingly. Syntax 1Return value
ExamplesUsing 0 to test if a property exist or not in a given object:
Object getOwnPropertyNames MethodThe 3 method takes an object as a parameter and returns and array of all its properties.Syntax 0Return value An array of strings of the passed object's properties. Examples 1If something other than an object is passed to 3, it will be coerced into an object before being returned as an array: 2Promise.prototype.thenA 5 function accepts two arguments and returns a Promise.The first argument is a required function that accepts one argument. Successful fulfillment of a Promise will trigger this function. The second argument is an optional function that also accepts one argument of its own. A thrown Error or Rejection of a Promise will trigger this function. 3 5 allows you to perform many asynchronous activities in sequence. You do this by attaching one 7 function to another separated by a dot operator. 4Map.prototype.entriesReturns a new 8 object that contains the 9 pairs for each element in the 0 object in insertion order.Syntax 5Example 6More info on objects in JavaScript:
More info about booleans:
ADVERTISEMENT ADVERTISEMENT ADVERTISEMENT If this article was helpful, tweet it. Learn to code for free. freeCodeCamp's open source curriculum has helped more than 40,000 people get jobs as developers. Get started How to set value in JavaScript object?You can create a JavaScript Set by:. Passing an Array to new Set(). Create a new Set and use add() to add values.. Create a new Set and use add() to add variables.. How to get value in object JavaScript?How to get Keys, Values, and Entries in JavaScript Object?. Object.keys(obj) – returns all the keys of object as array.. Object.values(obj) – returns all the values of the object as array.. Object.entries(obj) – returns an array of [key, value]. How can one assign value to the objects?Objects are assigned values using <- , an arrow formed out of . (An equal sign, = , can also be used.) For example, the following command assigns the value 5 to the object x . After this assignment, the object x 'contains' the value 5.
How to assign key to object in JavaScript?Object keys can be dynamically assigned in ES6 by placing an expression in square brackets. Syntax: var key="your_choice"; var object = {}; object[key] = "your_choice"; console. log(object);
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