如何对具有重用键的对象使用嵌套解构？

Question

I have a message from my websocket:

var message = {
  spell: {
    symbol: 'my-spell'
  },
  target: {
    symbol: 'my-target'
  }
};

I'm trying to learn destructuring, so I wrote the following code:

let {
  spell: {
    spell_symbol: symbol
  },
  target: {
    target_symbol: symbol = null
  }
} = message;
console.log('spell symbol: ' + spell_symbol);
console.log('target symbol: ' + target_symbol);

This gives me an error:

SyntaxError: Identifier 'symbol' has already been declared

Have I written the syntax wrong, or can you not reuse keys like symbol in your nested object? How would I extract target.symbol from message ?

Answer 1

You mixed up the order of property name and target expression, it should be

const {
  spell: {
    symbol: spell_symbol
  },
  target: {
    symbol: target_symbol = null
  }
} = message;
console.log('spell symbol: ' + spell_symbol);
console.log('target symbol: ' + target_symbol);