大整形

 // 大整形

      // let n = 521n;

      // console.log(n,typeof(n));

      // 函数

      // let n = 123;

      // console.log(BigInt(n));

      // 大数值 运算

      let max = Number.MAX_SAFE_INTEGER;

      console.log(max); // 9007199254740991

      console.log(max + 1); // 9007199254740992

      console.log(max + 2); // 9007199254740992

      console.log(BigInt(max)); // 9007199254740991n

      console.log(BigInt(max) + BigInt(1)); // 9007199254740992n

      console.log(BigInt(max) + BigInt(2)); // 9007199254740993n