function createNamedFunction(name, body) {

      return new Function("body", "return function " + name + "() {\n" + "    \"use strict\";" + "    return body.apply(this, arguments);\n" + "};\n")(body);

    };

    var errorName = 'InternalError';

    var errorClass = createNamedFunction(errorName, function (message) {

      this.name = errorName;

      this.message = message;

    });

动态方法生成问题：

以上写法再小程序中会提示 TypeError: (intermediate value) is not a function