iOS 第四期考核题（字符串／字典／数组的使用）

1.对字符串“2015-09-01 08:19:10”操作，输出"08:19:10"。要求使用两种截取方式。

2.数组中存取以下数据:

@[@{@"name":@"陈丰",@"age":@"32"},

@{@"name":@"孙明",@"age":@"24"},

@{@"name":@"王明",@"age":@"12"},

@{@"name":@"李西",@"age":@"50"}

]

1)按年龄进行排序(降序)，输出数据

2）删除“陈丰”并输出数据

NSString *str=@"2015-09-01 08:19:10";
NSRange range1=[str rangeOfString:@"08:19:10"];
NSString *subStr=[str substringWithRange:range1];
NSLog(@"第一题－－－－－－－（1）");
NSLog(@"%@",subStr);
NSString *substr1=[str substringFromIndex:range1.location];
NSLog(@"第一题－－－－－－－(2)");
NSLog(@"%@",substr1);

NSArray *arr1=@[@{@"name":@"陈丰",@"age":@"32"},
@{@"name":@"孙明",@"age":@"24"},
@{@"name":@"王明",@"age":@"12"},
@{@"name":@"李西",@"age":@"50"}
];

NSDictionary *dic1=@{@"name":@"陈丰",@"age":@"32"};
NSDictionary *dic2=@{@"name":@"孙明",@"age":@"24"};
NSDictionary *dic3=@{@"name":@"王明",@"age":@"12"};
NSDictionary *dic4=@{@"name":@"李西",@"age":@"50"};
NSMutableArray *arr=[[NSMutableArray alloc]initWithObjects:dic1,dic2,dic3,dic4,nil];
NSSortDescriptor *sorts=[[NSSortDescriptor alloc]initWithKey:@"age" ascending:YES];
[arr sortUsingDescriptors:[NSArray arrayWithObjects:sorts, nil]];
NSLog(@"第二题－－－－－－－（1）");
NSLog(@"排序后－－－－－－－(升序)");
for(NSDictionary *dic in arr){
NSLog(@"%@ %@",dic[@"name"],dic[@"age"]);
}
NSLog(@"排序后－－－－－－－(降序)");
NSSortDescriptor *sorts1=[[NSSortDescriptor alloc]initWithKey:@"age" ascending:NO];
[arr sortUsingDescriptors:[NSArray arrayWithObjects:sorts1, nil]];
for(NSDictionary *dic in arr){
NSLog(@"%@ %@",dic[@"name"],dic[@"age"]);
}
NSLog(@"第二题－－－－－－－（2）");
for(int i=0;i<[arr count];i++){
NSDictionary *dic=arr[i];
if([dic[@"name"] isEqual:@"陈丰"]){
[arr removeObject:dic];
}
}
for(NSDictionary *dic in arr){
NSLog(@"%@ %@",dic[@"name"],dic[@"age"]);
}