检测字符串中是否含有字母：
- (BOOL)containsLetters{
for (int i = 0; i < self.length; i++) {
unichar c = [self characterAtIndex:i];
if(((c > 64)&&(c < 91)) || ((c > 96)&&(c < 123))) {
return YES;
}
}
return NO;
}
检测字符串中是否含有大写字母：
- (BOOL)containsUpperCaseLetters{
for (int i = 0; i < self.length; i++) {
unichar c = [self characterAtIndex:i];
if((c > 64)&&(c < 91)) {
return YES;
}
}
return NO;
}
检测字符串中是否含有小写字母：
- (BOOL)containsLowerCaseLetters{
for (int i = 0; i < self.length; i++) {
unichar c = [self characterAtIndex:i];
if((c > 96)&&(c < 123)) {
return YES;
}
}
return NO;
}
