objective
时间: 2023-09-04 08:11:39 浏览: 35
Objective是Objective-C编程语言中的一个关键字,用于定义一个类的成员变量(Instance Variable)或方法(Method)。在Objective-C中,类的成员变量和方法都必须在类的实现文件中声明,而Objective关键字用于声明成员变量。例如:
```
@interface Person : NSObject {
@private
NSString *name;
NSInteger age;
}
- (void)sayHello;
@end
```
在上面的代码中,@interface关键字定义了一个Person类,并使用Objective关键字声明了name和age两个成员变量。同时,也声明了一个sayHello方法。注意,Objective关键字后面的变量名必须以小写字母开头,以便与类名和其他关键字区分开来。
相关问题
objective c
Objective-C 是一种面向对象的编程语言,是一种通用的编程语言,可以用于 iOS 和 macOS 应用程序的开发。它是由 Brad Cox 和 Tom Love 开发的,最早是作为 Smalltalk 编程语言的扩展而创建的。Objective-C 在语法上与 C 语言非常相似,但是它添加了面向对象的特性,例如类、对象、方法和继承等。Objective-C 是苹果公司最初使用的主要编程语言,现在已经被 Swift 语言所取代。但是,仍然有很多应用程序和库使用 Objective-C 编写,因此它仍然是一个重要的编程语言。
objective function
The objective function, also known as the loss function or cost function, is a mathematical function used to measure the difference between the predicted output and the actual output in a machine learning model. The goal of the objective function is to minimize this difference, which is also known as the error or loss. In supervised learning, the objective function is typically defined as a function of the model parameters that can be adjusted during training to improve the model's performance. The choice of objective function depends on the specific task and the type of model being used. Popular objective functions include mean squared error, cross-entropy loss, and hinge loss.