Question

Jarret Hardie（谢谢！）昨天发布此代码将NSinteget转换为二进制，并且工作正常，但我需要8位格式：

4 - ＆gt; 00000100

修改此代码的任何想法？

// Original author Adam Rosenfield... SO Question 655792
NSInteger theNumber = 56;
NSMutableString *str = [NSMutableString string];
for(NSInteger numberCopy = theNumber; numberCopy > 0; numberCopy >>= 1)
{
    // Prepend "0" or "1", depending on the bit
    [str insertString:((numberCopy & 1) ? @"1" : @"0") atIndex:0];
}

NSLog(@"Binary version: %@", str);

谢谢!!!!!!

Answer 1

这应该有效：

NSInteger theNumber = 56;
NSMutableString *str = [NSMutableString string];
NSInteger numberCopy = theNumber; // so you won't change your original value
for(NSInteger i = 0; i < 8 ; i++) {
    // Prepend "0" or "1", depending on the bit
    [str insertString:((numberCopy & 1) ? @"1" : @"0") atIndex:0];
    numberCopy >>= 1;
}

NSLog(@"Binary version: %@", str);

Answer 2

如果有人感兴趣，这是我的版本：

自动检测位数
尊重Coding Guidelines for Cocoa。

段：

NSString *NSStringWithBits(int64_t mask) {
    NSMutableString *mutableStringWithBits = [NSMutableString new];
    for (int8_t bitIndex = 0; bitIndex < sizeof(mask) * 8; bitIndex++) {
        [mutableStringWithBits insertString:mask & 1 ? @"1" : @"0" atIndex:0];
        mask >>= 1;
    }
    return [mutableStringWithBits copy];
}

Answer 3

参考，并支持@vincent osinga的答案..这是代码，包含在一个C函数..从NSUInteger返回二进制“字符串”..完美的记录按位typedef's等< / p>

- (NSString*) bitString:(NSUInteger) mask{
    NSString *str = @"";
    for (NSUInteger i = 0; i < 8 ; i++) {
      // Prepend "0" or "1", depending on the bit
      str = [NSString stringWithFormat:@"%@%@", 
                      mask & 1 ? @"1" : @"0", str];
      mask >>= 1;
    }
    return str;
}

我没有认为 NSInteger numberCopy = theNumber;是必要的，因为你没有使用指针，只是将原始值作为参数// so you won't change your original value。这将使用as / yield结果，如...

NSEventType anEvent = NSLeftMouseUp|NSLeftMouseDown;
NSLog(@"%@, %u\n%@, %u\n%@, %u\n%@, %u", 
    bitString( NSScrollWheel), NSScrollWheel,
    bitString( NSLeftMouseUp|NSLeftMouseDown),
               NSLeftMouseUp|NSLeftMouseDown, 
    bitString( anEvent ), anEvent, 
    bitString( NSAnyEventMask ), NSAnyEventMask);

NSLOG➞

00010110, 22  /* NSScrollWheel */
00000011, 3   /* NSLeftMouseUp | NSLeftMouseDown */
00000011, 3   /* same results with typedef'ed variable */
11111111, 4294967295  /* NSAnyEventMask */

NSInteger以8位格式表示二进制（字符串）值

3 个答案: