开发中const使用场景

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController
/*
    const开发中使用场景
    // 1.定义一个全局只读变量
    // 2.在方法中定义只读参数
 */

NSString * const name = @"123";

// 修饰对象
- (void)test:(NSString * const)name
{
    
}

// 修饰基本变量
- (void)test1:(int const)a
{
//    a = 3;
}

// 修饰指针变量
- (void)test2:(int const *)p
{
//    *p = 2;
    NSLog(@"%d",*p);
}

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [self test:@"123"];
    [self test1:2];
    int a = 10;
    [self test2:&a];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end```