iOS 改变字母的大小写(索引栏中使用过一次)

- (void)test{

NSString *testString = @"Hello World";

// lower case

NSString *lowerCaseString1 = [testString lowercaseString];

NSString *lowerCaseString2 = testString.lowercaseString;

// upper case

NSString *upperCaseString1 = [lowerCaseString1 uppercaseString];

NSString *upperCaseString2 = lowerCaseString1.uppercaseString;

NSLog(@"lowerCaseString1: %@",lowerCaseString1);

NSLog(@"lowerCaseString2: %@",lowerCaseString2);

NSLog(@"upperCaseString1: %@",upperCaseString1);

NSLog(@"upperCaseString2: %@",upperCaseString2);

// capitalize the first word of the sentence

NSString *txt = @"hi my friends!";

txt = [txt stringByReplacingCharactersInRange:NSMakeRange(0,1) withString:[[txt substringToIndex:1] uppercaseString]];

NSLog(@"txt: %@", txt);

}

打印结果：

2014-08-26 17:00:30.266 MyApp[68821:60b] lowerCaseString1: hello world

2014-08-26 17:00:30.267 MyApp[68821:60b] lowerCaseString2: hello world

2014-08-26 17:00:30.267 MyApp[68821:60b] upperCaseString1: HELLO WORLD

2014-08-26 17:00:30.267 MyApp[68821:60b] upperCaseString2: HELLO WORLD

2014-08-26 17:00:30.268 MyApp[68821:60b] txt: Hi my friends!