如何比较两个 arrays 并在 id 匹配时更改名称？

Question

I have a student array like below

student=[{id:1,name:'Sam',age:23},{id:2,name:'Jolia',age:23},{id:3,name:'Peter',age:23}]

And also I have another one which contains updated age values of some students like below for example

updated=[{id:2,age:25},{id:3,age:21}]

In this case I wanna find intersection by Id of these two arrays and change age values of student array with updated ones.

Expected Result

 student=[{id:1,name:'Sam',age:23},{id:2,name:'Jolia',age:25},{id:3,name:'Peter',age:21}]

values of id:2 and id:3 changed as updated includes those id values.

I tried to iterate two arrays by map but didn't work and didnt seem sensible to me.

updated.map(e=>{
   if(e.id==student.map(j=>{j.id})){
     e.age=j.age;
   }
 }) 

Answer 1

 var student=[{id:1,name:'Sam',age:23},{id:2,name:'Jolia',age:23},{id:3,name:'Peter',age:23}]; var updated=[{id:2,age:25},{id:3,age:21}]; updated.forEach(delta => { student.forEach(record => { if (delta.id === record.id) { record.age = delta.age; return false; } }); }); console.log(student);

You can use simple for each logic to iterate over each element to update them. Returning false in the inner forEach will result in it terminating once a match has been made.

Answer 2

 let updated=[{id:2,age:25},{id:3,age:21}]; let student=[{id:1,name:'Sam',age:23},{id:2,name:'Jolia',age:23},{id:3,name:'Peter',age:23}]; student.forEach(e =>{ let idx = updated.findIndex(u => u.id == e.id); if(idx >=0) { e.age = updated[idx].age; } }); console.log(student);

You can use forEach instead of map() for this scenario. Iterate over all students and update age based on the update array if id matches. findIndex returns the index of first element in the array that satisfies the provided testing function