React Redux不断返回多个reducer对象

Question

我试图仅渲染一个对象属性，但最终会渲染除目标属性之外未定义的所有其他对象。我对Redux，Reducer等还不是很陌生，所以任何帮助都会很棒！

// Letters reducer 
export default function() {
return [
    {
      x: {
        start: 10,
        finish: 100
      }
    },
    {
      y: {
        start: 20,
        finish: 100
      }
    },
    {
      z: {
        start: 30,
        finish: 100
      }
    }
  ];
}

组件

renderList() {
  this.props.letters.map(i => {
    console.log(i.x.start);
  });
}

控制台是

{current: 10, goal: 100}
2 undefined  < -- my Y and Z, which idk why it's getting called.

但是如果我尝试这样称呼它，它会起作用

console.log(this.props.letters[0].x.start)
// 10