JSON.parse()

JSON.parse()

const user = {
     
  name: 'John',
  email: '[email protected]',
  plan: 'Pro'
};
 
const userStr = JSON.stringify(user);
 
const newUserStr = JSON.parse(userStr, (key, value) => {
     
  if (typeof value === 'string') {
     
    return value.toUpperCase();
  }
  return value;
});
 
console.log(newUserStr); // => {name: "JOHN", email: "[email protected]", plan: "PRO"}

注：尾随逗号在JSON 中无效，所以如果传递给它的字符串有尾随逗号，JSON.parse()将会抛出错误。