如何在Objective c中逐字符映射字符串？

Question

我正在开发一种应用程序，因为我想将字符串的每个字符与其他字符共同映射。所以请告诉我该怎么做。

Answer 1

使用NSString characterAtIndex:函数按索引提取字符。

- (unichar)characterAtIndex:(NSUInteger)index

Answer 2

for (int i=0; i<[string length]; i++) {
   char = [string characterAtIndex:i];
   NSString *charString = [NSString stringWithFormat:@"%c", char];
   if ([charString isEqualToString:comparisonString]) {
      //match
   }
   else {
      //no match
   }
}

Answer 3

if you want to compare a string. Using isEqualToString method.

NSMutableString *str = [[NSMutableString alloc] initWithString:@"a"];
if([str isEqualToString:@"a"]){
  // match
}
else{
  // not match
}