javascript @param和@return注释中的感叹号表示什么？

Question

我正在尝试关注this guideline：

/** A class that does something. */
class SomeClass extends SomeBaseClass {
  /**
   * Operates on an instance of MyClass and returns something.
   * @param {!MyClass} obj An object that for some reason needs detailed
   *     explanation that spans multiple lines.
   * @param {!OtherClass} obviousOtherClass
   * @return {boolean} Whether something occurred.
   */
  someMethod(obj, obviousOtherClass) { ... }

  /** @override */
  overriddenMethod(param) { ... }
}

/**
 * Demonstrates how top-level functions follow the same rules.  This one
 * makes an array.
 * @param {TYPE} arg
 * @return {!Array<TYPE>}
 * @template TYPE
 */
function makeArray(arg) { ... }

而且我想知道感叹号在@param {!MyClass}或@return {!Array<TYPE>}中的含义以及何时使用它。

Answer 1

根据Use JSDoc: @type上的表，在“不可为空的类型”的行中，前面的感叹号表示“不可为空”。