Reverse strings in array objectivec [duplicate] - iphone

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Closed 10 years ago.
Possible Duplicate:
Reverse NSString text
i am new on objectovec. i have a array having strings. how to reverse each string?
which method of NSArray and NSstring will help me out?
i want reversed string in the array.
thanks

Answer 1

Create a method that will return a reversed string.
-(NSString *)reverseString:(NSString *)string{
NSString *reverseString=[NSString new];
for (NSInteger i=string.length-1; i>-1; i--) {
reverseString=[reverseString stringByAppendingFormat:#"%c",[string characterAtIndex:i]];
}
return reverseString;
}
In your any of the method :
NSMutableArray *names=[NSMutableArray arrayWithObjects:#"anoop",#"johnson",#"wasim",nil];
for (NSInteger i=0; i<names.count; i++) {
names[i]=[self reverseString:names[i]];
}
NSLog(#"%#",names);

Answer 2

Hope this help
NSString *str=textEntered.text;//
NSMutableArray *temp=[[NSMutableArray alloc] init];
for(int i=0;i<[str length];i++)
{
[temp addObject:[NSString stringWithFormat:#"%c",[str characterAtIndex:i]]];
}
temp = [NSMutableArray arrayWithArray:[[temp reverseObjectEnumerator] allObjects]];
NSString *reverseString=#"";
for(int i=0;i<[temp count];i++)
{
reverseString=[NSString stringWithFormat:#"%#%#",reverseString,[temp objectAtIndex:i]];
}
NSLog(#"%#",reverseString);

Answer 3

NSString *str=textEntered.text;//
NSMutableArray *temp=[[NSMutableArray alloc] init];
for(int i=0;i<[str length];i++)
{
[temp addObject:[NSString stringWithFormat:#"%c",[str characterAtIndex:i]]];
}
temp = [NSMutableArray arrayWithArray:[[temp reverseObjectEnumerator] allObjects]];
NSString *reverseString=#"";
for(int i=0;i<[temp count];i++)
{
reverseString=[NSString stringWithFormat:#"%#%#",reverseString,[temp objectAtIndex:i]];
}
NSLog(#"%#",reverseString);
AnOther way for revers string NSStringEnumerationOptions
- (NSString *)reverseString:(NSString *)string {
NSMutableString *reversedString = [[NSMutableString alloc] init];
NSRange fullRange = [string rangeOfString:string];
NSStringEnumerationOptions enumerationOptions = (NSStringEnumerationReverse | NSStringEnumerationByComposedCharacterSequences);
[string enumerateSubstringsInRange:fullRange options:enumerationOptions usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
[reversedString appendString:substring];
}];
return reversedString;
}

Answer 4

Use
unichar c[yourstring.Length];
NSRange raneg={0,yourstring.Length};
[yourstring getCharacters:c range:raneg];
//c will be an array of your string do what ever you wish

Answer 5

Use this one to reverse your string and then store back to your array at same index.
-(NSString*)reverseString:(NSString*)string {
NSMutableString *reversedString;
int length = [string length];
reversedString = [NSMutableString stringWithCapacity:length];
while (length--) {
[reversedString appendFormat:#"%c", [string characterAtIndex:length]];
}
return reversedString;
}
But if you have mutable string then you can create a category
#interface NSMutableString (Reverse)
- (void)reverseString;
#end
#implementation NSMutableString (Reverse)
- (void)reverseString {
for (int i = 0; i < self.length/2; i++) {
int l = self.length - 1 - i;
NSRange iRange = NSMakeRange(i, 1);
NSRange lRange = NSMakeRange(l, 1);
NSString *iStr = [self substringWithRange:iRange];
NSString *lStr = [self substringWithRange:lRange];
[self replaceCharactersInRange:iRange withString:lStr];
[self replaceCharactersInRange:lRange withString:iStr];
}
}
#end
And then you can use this category method like this
NSArray *arr = [NSArray arrayWithObjects:[#"hello" mutableCopy], [#"Do it now" mutableCopy], [#"Test string, 123 123" mutableCopy], nil];
NSLog(#"%#",arr);
[arr makeObjectsPerformSelector:#selector(reverseString)];
NSLog(#"%#",arr);