var student = {
id: 'st01',
name: 'Name 1',
age: 20,
address: {
street: 'street 1',
ward: 'ward 1'
}
}
var str = JSON.stringify(student);
console.log(str);
Output
{"id":"st01","name":"Name 1","age":20,"address":{"street":"street 1","ward":"ward 1"}}