根据属性判断对象的假值

淡淡的烟草味﹌ 2023-02-20 13:56 6阅读 0赞

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        <meta charset="UTF-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
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        <script>
          /* *@params obj <Object> checked object @params str <String> checked property @return bool <Boolean> @details whether Object or Array is undefined when get value by property; */
          function isFalseVal(obj, str) { 
            if (!obj) return false;
            if (typeof obj !== "object") return !!obj;
            if (Array.isArray(obj)) { 
              if (!obj.length) return false;
            }
            if (!str) return !!obj;
            let reg = /^(\.?[0-9a-zA-Z]+)+$/g;
            if (!reg.test(str) || str.indexOf(".") === 0) { 
              throw new Error("校验字符串格式只能为a.b.c");
            }
            let index = str.indexOf(".");
            let cur = index === -1 ? str : str.substring(0, index);
            let rest = index === -1 ? "" : str.substring(index + 1);
            let value = obj[cur];
            if (!!rest) { 
              let bool = isFalseVal(value, rest);
              if (!bool) return false;
            } else { 
              return isFalseVal(value, rest);
            }
            return true;
          }
          let arr = [{  a: [{  b: 3 }] }, [], [1]];
          let obj = {  a: {  b: { }, c: [], d: [1] } };
          let res = {  data: {  children: [{  list: [], items: [1] }] } };
          console.log(isFalseVal(arr, "0.a.0.b"));
          console.log(isFalseVal(arr, "0.a.0"));
          console.log(isFalseVal(arr, "0.a.0.c"));
          console.log(isFalseVal(arr, "1"));
          console.log(isFalseVal(arr, "2"));
          console.log(isFalseVal(obj, "a.b"));
          console.log(isFalseVal(obj, "a.b.c"));
          console.log(isFalseVal(obj, "a.c"));
          console.log(isFalseVal(obj, "a.d"));
          console.log(isFalseVal(res, "data.children.0.list"));
          console.log(isFalseVal(res, "data.children.0.items"));
        </script>
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    </html>