字符串翻转
记录一次面试题： i am a boy。 翻转成 boy。 a am i 保留空格
半翻转
代码
#
import "NSString+Reverse.h"
@implementation NSString (Reverse)
/**
翻转字符串
@return 待发展字符串
*/
- (NSString *)reverseString{
NSArray *strArray = [self componentsSeparatedByString:@
" "];
NSMutableArray *mArray = [NSMutableArray array];
for (NSInteger i = strArray.count -
1;i >=
0; i--) {
[mArray addObject:strArray[i]];
}
return [mArray componentsJoinedByString:@
" "];
}
结果：
全翻转
abc def。 翻转成 。fed cba
代码
/**
全翻转
@return 翻转后字符串
*/
- (NSString *)allReverse{
NSMutableString *reverseString = [NSMutableString string];
for (NSInteger i = self.length -
1 ; i >=
0; i--) {
unichar c = [self characterAtIndex:i];
NSString *s = [NSString stringWithCharacters:&c length:
1];
[reverseString appendString:s];
}
return reverseString;
}
结果
