第六讲 Block块语法及Block与数组的排序,ios字面量的使用(源代码上传)

#import <Foundation/Foundation.h>


#import "Student.h"

int c =200;
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        /*
     -------------------------------------
          定义block变量的四种方法
     -------------------------------------
         */
        //无返回值,无形参
        void (^myblock)() = ^(){
            NSLog(@"-------");
        };
        myblock();
        
        //无返回值有参数的block
        void (^lineBlock)(int) = ^(int n)
        {
            for (int i=0; i<n; i++) {
                NSLog(@"---------");
            }
        };
        lineBlock(5);
        //有返回值无形参
        int (^myblock3)() = ^(){
            int a=2;
            int b=3;
            return a+b;
        };
        int a =myblock3();
        NSLog(@"%d",a);

        //有返回值,有形参
        int (^sumblock)(int,int)=^(int a,int b)
        {
            return a+b;
        };
        int c = sumblock(10,11);
        NSLog(@"%d",c);
        
        
        
        
        /*
     ---------------------------------------
         
        Block的访问局部变量和全局变量的问题
         
     ----------------------------------------
         
         */
        
        
        
        int a1=8;  //全局变量
        void (^n)(int)=^(int a){
        //  a=7;  //局部变量(重名时优先使用)
            NSLog(@"---===%d",a1);
            NSLog(@"%p",&a1);
        };
        n(a);
        NSLog(@"----%d",a1);
        NSLog(@"%p",&a1);
        
        //block内部可以访问外部局部变量的值,如果想要修改要用__block
        __block  int a2=8;//使用__block可以修改局部变量
        NSLog(@"------%p",&a2);
        void (^myblock1)()=
        ^{
            a2=7;
            NSLog(@"---%d",a2);
            NSLog(@"-%p",&a2);
        };
        myblock1(a);
        NSLog(@"--%d",a2);
        NSLog(@"------%p",&a2);
        
        //block内部  可以使用  外界的局部变量
        __block int num = 1;
        void (^addNum)() = ^()
        {
            //在block内部实现面部分,访问不到局部变量
            //但是当使用__block后就可以修改局部变量
            num++;
            int c = num*10;
            NSLog(@"%d",c);
        };
        
        //调用block
        addNum();
        NSLog(@"count = %d",num);
        
        
        //block 与全局变量
        //在block内部可以访问全局变量,并且可以修改全局变量
        
        /*
         //int c = 200;定义在main上面
         
         void (^add)() = ^()
         {
         c++;
         NSLog(@"c = %d",c);
         };
         add ();
         NSLog(@"---%d",c);
         
         
         */
        
        
    /*
   -------------------------------------------
         Block与数组的配合使用(多用于排序)
    --------------------------------------------
    */
        
        
        
        
        //利用block与对数组进行排序(此种方式默认为升序)
        
        NSArray *array = [NSArray arrayWithObjects:@"as",@"er",@"hfg", nil];
        NSComparator sortBlock = ^(id string1, id string2){
            
            return [string1 compare:string2];
            
        };
        NSArray *sortArray = [array sortedArrayUsingComparator:sortBlock];
        NSLog(@"%@",sortArray);

        
        /*
        students是⼀一个NSMutableArray对象,包含若干个Student对象。按
        student的age进⾏行排序。对姓名进行排序.(student需要自己定义)
         
        */
        Student *stu1 = [[Student alloc]initWithName:@"aiaohua" number:@"b1" age:12];
        Student *stu2 = [[Student alloc]initWithName:@"xiaoming" number:@"b2" age:15];
        Student *stu3 = [[Student alloc]initWithName:@"giaowang" number:@"b3" age:14];
        Student *stu4 = [[Student alloc]initWithName:@"oiaofang" number:@"b4" age:11];
        
        NSMutableArray *num1 = [NSMutableArray arrayWithObjects:stu1,stu2,stu3,stu4, nil];
        
         [num1 sortUsingComparator:
                    ^NSComparisonResult(id a, id b)
        {
            Student *st1 = (Student*)a;
            Student *st2 = (Student*)b;
            if ([st1 age]>[st2 age]) {
                return NSOrderedDescending;
            }
            else if([st1 age]<[st2 age]){
                return NSOrderedAscending;
            }else {
                return NSOrderedSame;
            }
  
         }];
        //用description方法重写后得出结果
        NSLog(@"%@",num1);
 
        //按照姓名顺序打印
    [num1 sortUsingComparator:^NSComparisonResult(id a,id b)
        {
            Student *a1 = (Student*)a;
            Student *b1 = (Student*)b;
            if ([[a1 name] compare:[b1 name]]>0) {
                return NSOrderedDescending;
        } else if ([[a1 name] compare:[b1 name]]<0)
            {
                return NSOrderedAscending;
            }else{
                return NSOrderedSame;
            }
 
        }];
        
        for (int i=0; i<[num1 count]; i++) {
            NSLog(@"%@",[num1[i] name]);
        }

     /*
      
  ------------------------------------------
               ios的字面量
  ------------------------------------------
      
      */
        
     //一般方法输出数组,字符串,字典,集合
        
        
        //数组
        NSArray *arr = [[NSArray alloc]initWithObjects:@"123",@"456",@"678", nil];
        NSLog(@"%@",arr);
        NSArray *arr1 = [NSArray arrayWithObjects:@"21",@"43",@"65", nil];
        NSLog(@"%@",arr1);
        //字符串
        NSString *str = [NSString stringWithFormat:@"%s %d%c","sdf",34,'d'];
        NSLog(@"%@",str);
        NSString *str1 = [NSString stringWithUTF8String:"huige"];
        NSLog(@"%@",str1);
        NSString *str2 = [NSString stringWithString:str1];
        NSLog(@"%@",str2);
        //字典
        NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:@"one",@"1",@"two",@"2",@"three",@"3", nil];
        NSLog(@"%@",dic);
        NSDictionary *dic1 = [NSDictionary dictionaryWithDictionary:dic];
        NSLog(@"%@",dic1);
        //集合
        NSSet *set = [NSSet setWithObjects:@"hui",@"deng",@"xiao", nil];
        NSLog(@"%@",set);
        NSSet *set1 = [[NSSet alloc]initWithObjects:@"one",@"two",@"three", nil];
        NSLog(@"%@",set1);
        
        
       //用ios字面量定义数组,字符串,字典
        //定义字符串
        NSString *str3 = @"hollow";
        NSLog(@"%@",str3);
        //定义数组
        NSArray *arr3 = @[@"12",@"53",@"67"];
        NSLog(@"%@",arr3);
        //输出指定元素
        NSLog(@"--%@",arr3[2]);
        //定义字典
        NSDictionary *dic3 = @{@"1":@"one",@"2":@"two",@"3":@"three"};
        NSLog(@"%@",dic3);