相关疑难解决方法(0)

const value = Math.random() < 0.5 ? "a" : "b";
if (value !== "a") {
  // ...
} else if (value === "b") {
This condition will always return 'false' since the types '"a"' and '"b"' have no overlap.

  // Oops, unreachable
}

在教程中找到了这段代码。我想了解这个错误的含义："types '"a"' and '"b"' have no overlap."

他们在说什么？