NSPredicate的在查询中的简单使用

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代码吧,每块代码都可以直接跑,并附有注释和运行结果

  1. //直接使用 == 严格匹配
  2. NSArray *arrOriginal = [NSArray arrayWithObjects:@"c1",@"c",@"cd",@"cdd",nil];
  3. NSString *match = @"cd";
  4. NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF == %@",match];
  5. NSArray *results = [arrOriginal filteredArrayUsingPredicate:predicate];
  6. NSLog(@"result===%@",results);

打印结果:
result===(
cd,
cd
)
  1. //like匹配,类似sql中的用法
  2. NSArray *arrOriginal = [NSArray arrayWithObjects:@"c1",@"d",@"dd",@"dcd",@"cdc",nil];
  3. NSString *match = @"c*";//以c开头
  4. NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF like %@",results);

打印结果:
result===(
c1,
cd,
cdd,
cdc
)
  1. //忽略大小写进行匹配
  2. NSArray *arrOriginal = [NSArray arrayWithObjects:@"Cdd",@"cDc",@"dcdd",nil];
  3. NSString *match = @"cd*";
  4. NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF like[c] %@",results);

打印结果:
result===(
Cdd,
cDc,
cdd
)
  1. //利用正则表达是进行过滤
  2. NSArray *arrOriginal = [NSArray arrayWithObjects:@"c1",@"C3",@"d2",@"c2",nil];
  3. NSString *match = @"^c\\d?";
  4. NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@",
    c2

  5. )
  6. //利用过滤器(数组)进行过滤
  7. NSArray *arrFilter = [NSArray arrayWithObjects:@"aa",@"bb",nil];
  8. NSArray *arrOriginal = [NSArray arrayWithObjects:@"dds",@"c1",@"aa",nil];
  9. NSPredicate *predicate  = [NSPredicate predicateWithFormat:@"NOT (SELF in %@)",arrFilter];//不包含符合过滤器的内容
  10. NSArray *results = [arrOriginal filteredArrayUsingPredicate:predicate];
  11. NSLog(@"result===%@",results);
    打印结果: result===( dds,c1,C3,c2 )

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