问为什么当我更改find()返回的值时，原始数组会发生更改

EN

const courses = [
    {'id':101,'name':'Complete Web Dev'},
    {'id':102,'name':'DS and Algo'},
    {'id':103,'name':'React'}
];

let num = courses.find(c=>{
  if(c.id===102)
    return c;
});

num.name="Programming Fundamentals"
console.log(courses);

[
  { id: 101, name: 'Complete Web Dev' },
  { id: 102, name: 'Programming Fundamentals' },
  { id: 103, name: 'React' }
]