Question

有没有一种方法可以捕获尚未在类中设置的所有字段？我正在解析json文件，有时字段名称会更改，我想知道尚未设置哪些字段使其更易于修复。以下是我用来设置类中字段的代码示例。这只是一个小样本，我的课程有250多个字段，因此无法一一检查。

const myLand = new mls.Land();
    myLand.landLease = trimString(data["LAND LEASE?"]);
    myLand.commonInterest = trimString(data["COMMON INTEREST"]);
    myLand.landLeaseAmount = trimString(data["LAND LEASE AMOUNT"]);
    myLand.landLeaseAmtFreq = trimString(data["LAND LEASE AMT FREQ"]);
    myLand.landLeasePurch = trimString(data["LAND LEASE PURCH?"]);
    myLand.landLeaseRenew = trimString(data["LAND LEASE RENEW"]);

newListing.land = myLand;

这是Trim函数

function trimString(inputStr: string) {
    return (inputStr !== undefined && typeof inputStr === "string") ? inputStr.trim() : undefined;
  }

Answer 1

使用filter的{{3}}，value和map的{{1}}。

key

Answer 2

如果您需要检查代表类的对象的keys的设置为undefined，则可以使用Object.keys()和Array.filter()，如下所示：

function trimString(inputStr)
{
    return (inputStr !== undefined && typeof inputStr === "string") ? inputStr.trim() : undefined;
}

const myLand = {};
myLand.landLease = trimString("123");
myLand.commonInterest = trimString(" common interest ");
myLand.landLeaseAmount = trimString(null);
myLand.landLeaseAmtFreq = trimString({});

let undefinedKeys = Object.keys(myLand).filter(k => myLand[k] === undefined);

console.log("Undefined fields:", undefinedKeys);

.as-console {background-color:black !important; color:lime;}
.as-console-wrapper {max-height:100% !important; top:0;}

Answer 3

您可以只创建一个 expected 字段数组，然后过滤这些字段：

const expectedFields = ["LAND LEASE?", "COMMON INTEREST", "LAND LEASE AMOUNT", "LAND LEASE AMT FREQ", "LAND LEASE PURCH?", "LAND LEASE RENEW"];

const absentFields = expectedFields.filter(field => !(field in data));

如果您还想捕获非字符串类型的字段：

const absentFields = expectedFields.filter(field => typeof data[field] !== "string");

您分配数据的例程也可以放在循环中：

const camelCase = field => field.match(/\w+/g).map((word, i) => (i ? word[0] : "") + word.slice(+!!i).toLowerCase()).join``;

const expectedFields = ["LAND LEASE?", "COMMON INTEREST", "LAND LEASE AMOUNT", "LAND LEASE AMT FREQ", "LAND LEASE PURCH?", "LAND LEASE RENEW"];

// Sample data
const data = { "LAND LEASE?": "a", "LAND LEASE AMOUNT": "n" }

const myLand = {};
for (const field of expectedFields) {
    const value = data[field];
    if (typeof value === "string") myLand[camelCase(field)] = value.trim();
}

console.log(myLand);
console.log("missing:", expectedFields.filter(field => typeof data[field] !== "string"));

如何检查是否设置了class元素？

3 个答案: