1.搜索的string获取

NSArray *array = @[@"Abc", @"Beijing", @"12Bei"];

//区分

NSPredicate *predt0 = [NSPredicate predicateWithFormat:@"self contains %@",@"B"];

NSLog(@"--区分---%@",[array filteredArrayUsingPredicate:predt0]);

// 不区分

NSPredicate *predt1 = [NSPredicate predicateWithFormat:@"self contains [cd] %@",@"B"];

NSLog(@"---不区分--%@",[array filteredArrayUsingPredicate:predt1]);

2.直接的比较

区分的：系统的就默认区分。

不区分：

BOOL result0 = [@"Beijing" caseInsensitiveCompare:@"beijing"] == NSOrderedSame;

NSLog(@"--result0-----:%d",result0);

BOOL result1 = [@"Beijing" compare:@"beijing" options:NSCaseInsensitiveSearch | NSNumericSearch] == NSOrderedSame;

NSLog(@"--result1-----:%d",result1);