數(shù)組中元素按照一定規(guī)則排序

主要是NSSortDescriptor這個(gè)類 代碼

NSArray *array = @[@"one", @"two", @"three", @"four", @"six"];
    
    //創(chuàng)建一個(gè)排序條件，也就是一個(gè)NSSortDescriptor對(duì)象
    
    //其中第一個(gè)參數(shù)為數(shù)組中對(duì)象要按照什么屬性來(lái)排序(比如自身、姓名，年齡等)
    
    //第二個(gè)參數(shù)為指定排序方式是升序還是降序
    
    //ascending  排序的意思，默認(rèn)為YES 升序
    
    NSSortDescriptor *des = [[NSSortDescriptor alloc] initWithKey:@"self" ascending:YES];
    
    NSArray *newArray = [array sortedArrayUsingDescriptors:@[des]];
    
    NSLog(@"%@",newArray);

多條件排序

Person *p1 = [[Person alloc] initWithName:@"zhonger" age:@"19"];
    Person *p2 = [[Person alloc] initWithName:@"zhubada" age:@"11"];
    Person *p3 = [[Person alloc] initWithName:@"zhubada" age:@"1"];
    Person *p4 = [[Person alloc] initWithName:@"zhubada" age:@"33"];
    Person *p5 = [[Person alloc] initWithName:@"hehehe" age:@"38"];
    NSArray *person = @[p1, p2, p3, p4, p5];
    
    NSSortDescriptor *des1 = [[NSSortDescriptor alloc]initWithKey:@"name" ascending:NO];
    
    NSSortDescriptor *des2 = [[NSSortDescriptor alloc] initWithKey:@"age" ascending:NO];
    // 可以用sortedArrayUsingDescriptors:方法實(shí)現(xiàn)把多個(gè)排序條件放到數(shù)組中，實(shí)現(xiàn)多條件排序，按數(shù)組先后順序，先加入的優(yōu)先級(jí)高

    NSArray *newArray1 = [person sortedArrayUsingDescriptors:@[des1,des2]];
    for (Person *p in newArray1) {
        NSLog(@"姓名：%@ , 年齡：%@",p.name,p.age);
        
    }

注意這兩個(gè)方法 可變數(shù)組和不可變數(shù)組

Snip20170321_3.png