如何在NSMutableArray中实现“按值分组”？
如何在NSMutableArray中实现“按值分组”？
提问于 2011-12-20 06:39:15
我正在使用NSMutableArray。我想按日期获取值，就像在SQL group by "log_date"中那样。
logMuArray (
{
"log_currenttime" = "4:30pm";
"log_date" = "11.12.2011";
"log_duration" = "1:30";
},
{
"log_currenttime" = "4:33pm";
"log_date" = "11.12.2011";
"log_duration" = "2:21";
},
{
"log_currenttime" = "4:40pm";
"log_date" = "11.12.2011";
"log_duration" = "5:30";
},
{
"log_currenttime" = "7:30pm";
"log_date" = "12.12.2011";
"log_duration" = "1:30";
},
{
"log_currenttime" = "7:33pm";
"log_date" = "12.12.2011";
"log_duration" = "2:21";
},
{
"log_currenttime" = "7:40pm";
"log_date" = "12.12.2011";
"log_duration" = "5:30";
},
{
"log_currenttime" = "07:16pm";
"log_date" = "19.12.2011";
"log_duration" = "0:07";
},
{
"log_currenttime" = "7:31pm";
"log_date" = "19.12.2011";
"log_duration" = "0:04";
},
{
"log_currenttime" = "7:33pm";
"log_date" = "19.12.2011";
"log_duration" = "0:03";
},
{
"log_currenttime" = "7:33pm";
"log_date" = "19.12.2011";
"log_duration" = "0:06";
},
{
"log_currenttime" = "7:35pm";
"log_date" = "19.12.2011";
"log_duration" = "0:05";
}
)**所以，我刚刚表演了.
NSLog(@"logMuArray %@",[logMuArray valueForKey:@"log_date"]);但是我只想获取唯一的日期。**我考虑过NSPredicate或可变集等等。
logMuArray (
"11.12.2011",
"11.12.2011",
"11.12.2011",
"12.12.2011",
"12.12.2011",
"12.12.2011",
"19.12.2011",
"19.12.2011",
"19.12.2011",
"19.12.2011",
"19.12.2011"
)提前谢谢.
编辑：
我也听说过"@distinctUnionOfObjects“
.
Stack Overflow用户
发布于 2011-12-20 06:50:12
您应该将NSSet用于以下特殊项目：
NSSet *filteredData = [NSSet setWithArray:[logMuArray valueForKey:@"log_date"]];页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/8571646
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