var arr= [{name:'xyz'},{name:'abc'}];
arr.forEach(function(a){
a.age = 25;
a.country = 'USA'
a.technology = 'JavaScript'
});
How can I add these dynamic key-value pair with spread operator using ES6 syntax
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1Why do you want to use spread syntax ("Spread syntax allows an iterable such as an array expression or string to be expanded in places where zero or more arguments (for function calls) or elements (for array literals) are expected, or an object expression to be expanded in places where zero or more key-value pairs (for object literals) are expected.")?Andreas– Andreas2018-03-23 12:17:01 +00:00Commented Mar 23, 2018 at 12:17
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why spread operator?Nina Scholz– Nina Scholz2018-03-23 12:47:37 +00:00Commented Mar 23, 2018 at 12:47
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3 Answers
arr = arr.map(prev => ({ ...prev, age: 25, country:"USA" }));
4 Comments
Sheena
Hi, I want this with forEach loop
Luis felipe De jesus Munoz
map is a foreach loop
brunnerh
@Sheena: No you don't.
Sheena
@Luis felipe De jesus Munoz: I want to use forEach because I don't want to return a new array , I want to update the array – Sheena 8 mins ago
I don't think you can use spread syntax to modify an object, only to create a new object. If you want something that allows you to use a Javascript object literal to modify, use Object.assign()
arr.forEach(a => Object.assign(a, {
age: 25,
country: 'USA',
technology: 'Javascript'
}));
1 Comment
Barmar
@GerardoFurtado SO desperately needs a paren-matcher :)
Simply use this code:
var arr= [{name:'xyz'},{name:'abc'}];
var obj = {
age: 25,
country: 'USA',
technology: 'JavaScript'
};
arr.forEach(function(a){
Object.assign(a, obj);
});
console.log(arr);
1 Comment
yivi
While this code snippet may be the solution, including an explanation really helps to improve the quality of your post. Remember that you are answering the question for readers in the future, and those people might not know the reasons for your code suggestion.