js在数组中添加一个新元素

Question

我正在开发节点js应用程序，我面临的问题是必须在数组中添加位置点，但是每个位置点是不同的，比如第一个数组/对象需要10个，然后下一个数组/对象必须是7个。

​

let converter = [
  { name: 'team-1', killPoint: 8 },
  { name: 'team-2', killPoint: 7 },
  { name: 'team-7', killPoint: 56 },
  { name: 'team-9', killPoint: 68 }
]
const pointsystem = [10, 7, 6, 5, 4, 3, 2, 1, 0];
const positionAdd = (objects) => {
  let i = 0
  const posRes = {};
  objects.forEach(({
    name,
    killPoint
  }) => {
    posRes[name] = posRes[name] || {
      name,
      positionPoint: 0,
      killPoint: 0,
    };
    posRes[name].positionPoint = pointsystem[i+1];
    posRes[name].killPoint = killPoint;
  });
  return Object.values(posRes);
};
console.log(positionAdd(converter));

​

尝试使用这段代码，但它的工作不像需要的那样

输出不足

[
  { name: 'team-1', positionPoint: 10, killPoint: 8 },
  { name: 'team-2', positionPoint: 7, killPoint: 7 },
  { name: 'team-7', positionPoint: 6, killPoint: 56 },
  { name: 'team-9', positionPoint: 5, killPoint: 68 }
]

如果有更多的队伍，那么点应该持续到0.

Answer 1

使用map()而不是附加到结果数组。

使用回调函数的第二个参数获取数组索引，并使用该参数对pointsystem进行索引。

使用对象扩展语法将其合并到来自converter的对象中。

​

let converter = [
  { name: 'team-1', killPoint: 8 },
  { name: 'team-2', killPoint: 7 },
  { name: 'team-7', killPoint: 56 },
  { name: 'team-9', killPoint: 68 }
]
const pointsystem = [10, 7, 6, 5, 4, 3, 2, 1, 0];
const positionAdd = (objects) => objects.map((obj, i) => ({...obj, positionPoint: pointsystem[i]}));

console.log(positionAdd(converter));

​

Answer 2

以下内容还将更改原始对象。我不知道OP的目的是：

​

const data = [
  { name: 'team-1', killPoint: 8 },
  { name: 'team-2', killPoint: 7 },
  { name: 'team-7', killPoint: 56 },
  { name: 'team-9', killPoint: 68 }
],points = [10,7,6,5,4,3,2,1,0];
console.log(data.map((d,i)=>{
 d.positionPoint=points[i]??0;
 return d;
}));

​

Answer 3

您正在向变量i中添加1，而不是在每个循环之后实现i。每次迭代后，您需要将i增加1。

示例：

posRes[name].positionPoint = pointsystem[i];
i += 1;

测试：

​

let converter = [
  { name: 'team-1', killPoint: 8 },
  { name: 'team-2', killPoint: 7 },
  { name: 'team-7', killPoint: 56 },
  { name: 'team-9', killPoint: 68 }
]
const pointsystem = [10, 7, 6, 5, 4, 3, 2, 1, 0];
const positionAdd = (objects) => {
  let i = 0
  const posRes = {};
  objects.forEach(({
    name,
    killPoint
  }) => {
    posRes[name] = posRes[name] || {
      name,
      positionPoint: 0,
      killPoint: 0,
    };
    posRes[name].positionPoint = pointsystem[i];
    i += 1;
    posRes[name].killPoint = killPoint;
  });
  return Object.values(posRes);
};
console.log(positionAdd(converter));

​