To convert a objects to strings we can use JSON.stringify() or String() functions. Here is an example follows.

// program to convert an object to a string

const emp = {
    name: 'John',
    age: 30
}

const empInfo =  JSON.stringify(emp);

console.log(empInfo);
console.log(typeof emp);

Out put:

{"name":"John","age": 30}
string

// program to convert an object to a string

const emp = {
    name: 'John',
    age: 30
}

const empInfo1 = String(emp);
const empInfo2 = String(emp['name']);

console.log(empInfo1);
console.log(empInfo2);

console.log(typeof empInfo1);

Output:

[object Object]
Jack
string