替换字符串中的字符 [英] Replace character in string
本文介绍了替换字符串中的字符的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有一个 NSMutableString
@hello
。我想替换第二个位置的字符,'e'替换为'a',以便它读取 @hallo
。
I have a NSMutableString
@"hello"
. I'd like to replace the character at the second position, 'e' with 'a' so that it reads @"hallo"
. How do I do that?
我已经尝试过实现一个Shift Cipher,但它抛出一个 IndexOutBoundsException
/ p>
I have tried this to implement a Shift Cipher, but it throws an IndexOutBoundsException
- (NSString*)encode:(NSString*)original withShift:(int)shift {
NSMutableString* encoded = [NSMutableString stringWithString:original];
for (int i=0; i < [encoded length]; i++) {
char oriChar = [encoded characterAtIndex:i];
if (oriChar == ' ') {
continue;
}
char encChar = ((oriChar - LETTER_POS) + shift) % ALPHABET_LENGTH + LETTER_POS;
NSRange range = {i, i};
[encoded replaceCharactersInRange:range withString:[NSString stringWithUTF8String:&encChar]];
}
return encoded;
}
推荐答案
NSRange r = {1,1}; //String indexing is 0-based
[s replaceCharactersInRange: r withString:@"a"]
另外,请学习使用在线参考。
Also, do learn to use the online reference.
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