地图内的 if 语句

Posted 2023-02-16

【中文标题】地图内的 if 语句

【英文标题】：If Statement Inside Map

【发布时间】：2022-01-19 02:54:18

【问题描述】：

我目前有一个 DataGrid，它正在渲染从我的后端 mongoDB 抓取的数据。数据渲染映射到 mongoDB 文档中的对象指定的键。在每个文档中都有一组布尔值，我正在尝试检查其中任何一个是否为真，如果它们为真，它将在每行的 repairsNeeded 列中呈现一个 Y，如果不是，它将呈现一个 N。我遇到的主要问题是在哪里/如何检查这个。我尝试了一些不同的想法，但无济于事。现在，我为 document.isPowerCordDamaged（我的布尔值之一）分配了每一行的 repairsNeeded 列，这取决于它是否被选中。

代码：

function Rounding() 
  const [cartsRounded, setCartsRounded] = useState([]);

  let navigate = useNavigate();

  useEffect(() => 
    userCartsRounded()
      .then((response) => 
        setCartsRounded(response.data);
      )
      .catch((err) => 
        console.log(err);
      );
  , []);

  const columns = [
    
      field: "serialNum",
      headerName: "Cart Serial Number",
      width: 250,
    ,
    
      field: "pcNum",
      headerName: "Workstation Number",
      width: 250,
    ,
    
      field: "dateLastRounded",
      headerName: "Last Rounded On",
      width: 250,
    ,
    
      field: "repairsNeeded",
      headerName: "Repairs?",
      width: 100,
    ,
    
      field: "quarter",
      headerName: "Quarter",
      width: 75,
    ,
  ];

  const [sortModel, setSortModel] = React.useState([
    
      field: "dateLastRounded",
      sort: "desc",
    ,
  ]);

  const rows = useMemo(
    () =>
      cartsRounded.map((row, index) => (
        ...row,
        id: index,
        serialNum: row.cartSerialNumber,
        pcNum: row.pcNumber,
        dateLastRounded: moment(row.updatedAt).format("MM-D-YYYY"),
        repairsNeeded: row.isPowerCordDamaged,
        quarter: moment(row.updatedAt).format("Qo"),
      )),
    [cartsRounded]
  );

  return (
    <div>
      <IconButton
        color="primary"
        aria-label="new rounding"
        component="span"
        onClick=() => 
          navigate("add_new_cart");
        
      >
        <AddCircleOutline />
      </IconButton>
      <div style= height: 400, width: "100%" >
        <DataGrid
          component=Paper
          rows=rows
          columns=columns
          sortModel=sortModel
          pageSize=100
          rowsPerPageOptions=[100]
        />
      </div>
    </div>
  );


export default Rounding;

文档示例：

  
    _id: new ObjectId("61b95e447aec51d938e856cc"),
    cartSerialNumber: 'testytitit',
    pcNumber: '14124f0sdf0sfs',
    isPowerCordDamaged: false,
    isFuseBlown: false,
    isInverterBad: false,
    isInterfaceDamaged: false,
    isPhysicalDamage: false,
    otherNotes: '',
    roundedBy: '6186c13beb18d33d5088f7b2',
    createdAt: 2021-12-15T03:17:24.495Z,
    updatedAt: 2021-12-15T03:17:24.495Z,
    __v: 0
  

【参考方案1】：

我可能不理解这里的问题。但我认为您要做的是让 repairsNeeded 字段具有 Y 或 N 而不是其布尔值。

试试这个。

const rows = useMemo(
    () =>
      cartsRounded.map((row, index) => (
        ...row,
        id: index,
        serialNum: row.cartSerialNumber,
        pcNum: row.pcNumber,
        dateLastRounded: moment(row.updatedAt).format("MM-D-YYYY"),
        repairsNeeded: row.isPowerCordDamaged ? "Y" : "N" // short hand for if (row.isPowerCordDamaged === true) return "Y" else return "N",
        quarter: moment(row.updatedAt).format("Qo"),
      )),
    [cartsRounded]
  );

看完之后，如果有的话，你可能想返回 Y 或 N？在这种情况下，最好将其拉入一个函数中。

const isRepairNeeded = (row) => 

  if (row.isPowerCordDamaged) return "Y";
  if (row.isFuseBlown) return "Y";
  ... rest of the ifs
  return "N"; // N is only returned if none of the if statements === true;


const rows = useMemo(
    () =>
      cartsRounded.map((row, index) => (
        ...row,
        id: index,
        serialNum: row.cartSerialNumber,
        pcNum: row.pcNumber,
        dateLastRounded: moment(row.updatedAt).format("MM-D-YYYY"),
        repairsNeeded: isRepairNeeded(row) // call the function will return "Y" or "N",
        quarter: moment(row.updatedAt).format("Qo"),
      )),
    [cartsRounded]
  );