C/Objective C指针声明

Question

我有一个函数,需要一个类型的参数float**,但我不知道如何声明和初始化这个变量.

任何人都可以给我任何建议吗？更好的是,它是什么类型的变量？我已经查了几天了,任何搜索结果都是空的.

谢谢

编辑

这是有问题的功能

    - (OSStatus)getBuffersInner:(float**)buffers numberOfBuffers:(int)chnls samples:(int)samples
    {
        int i, j ;
        UInt32 frames ;

        // zero out requested buffers if client needs more channels than exist in the channel map
        for ( i = numberOfMappedChannels; i < chnls; i++ ) memset( buffers[i], 0, samples*sizeof( float ) ) ;

        //  place buffer pointers into bufferList, following the channelMap
        for ( i = 0; i < fileDescriptor.mChannelsPerFrame; i++ ) {
            j = inverseChannelMap[i] ;
            resampledBufferList.list.mBuffers[i].mData = ( j < 0 || j >= chnls ) ? zeros : buffers[j] ;
        }
        frames = samples ;
        return ExtAudioFileRead( audioFileRef, &frames, &resampledBufferList.list ) ;
    }

Answer 1

这是一个指向指针的指针.以下是一个示例用法:

float f = 0.123;
float *pf = &f;
float **ppf = &pf;

cout << *pf << " == " << **ppf << endl;

你可能想看看这个.