如何在javascript扩展运算符中与嵌套键合并？

Question

I have the following objects like

obj1 = { key1: { a: 1}}

I want to merge the following object with the above

key1 = { b: 2}

I want to get the result as following by merging the key1 with the existing key in the first object.

{key1: {a: 1, b: 2}} 

How can I do this using spread operator in javascript? Thanks in advance.

Answer 1

You can spread both existing and new object

Note: Using spread operator will only merge the enumerable properties.

 const obj1 = { key1: { a: 1}} const key1 = { b: 2}; const res = {...obj1,key1:{...obj1.key1,...key1}}; console.log(res) 

If you want to modify the original object then only change obj.key1

 const obj1 = { key1: { a: 1}} const key1 = { b: 2}; obj1.key1 = {...obj1.key1,...key1} console.log(obj1) 

Answer 2

Just use the spread operator like so:

 let obj1 = { key1: { a: 1 } }; let key1 = { b: 2 }; obj1.key1 = { ...obj1.key1, ...key1 }; console.log(obj1); 

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Answer 3

You could splead it into the wanted property.

 var obj1 = { key1: { a: 1 } }, key1 = { b: 2 }; obj1.key1 = { ...obj1.key1, ...key1 }; console.log(obj1); 

Answer 4

You should use Object.assign

 var obj1 = { key1: { a: 1}}; var key1 = { b: 2}; Object.assign(obj1.key1, key1); console.log(obj1) 

Answer 5

Try this:

 let obj1 = { key1: { a: 1}} let b = { b: 2} let a = obj1.key1; //{a:1} // merge using spread operator let key1 = {...a, ...b}; //{a:1, b:2} obj1.key1 = key1; //{"a":1,"b":2"} console.log(obj1) //{ "key1":{"a":1,"b":2"}}