c++ string练习记录

 //1.实现strcpy.    

char* MyStrCpy( char *pDest, const char *pSrc )
{
    if( pSrc == NULL || pDest == NULL )
    {
        return NULL;
    }

    if( pDest == pSrc)
    {
        return pDest;
    }
    char *ret = pDest; 

    while(1)
    {
        *pDest = *pSrc;
        if( *pDest == '\0')
        {
            break;
        }
        else
        {
            pDest++;
            pSrc++;
        }
    
    }


    return ret;
}

 

//2.实现strcat.    

char* MyStrCat( char *pDest, const char *pSrc )
{

    if( pDest == NULL )
    {    
        return NULL;
    }
    if( pSrc == NULL )
    {
        return pDest;
    }

    char *ret = pDest;

    while( *pDest != '\0')
    {
        pDest++;
        
    }
    while( 1 )
    {
        *pDest = *pSrc;
        if(*pDest == '\0')
        {
            break;
        }
        else
        {
            pDest++;
            pSrc++;
        }

    }

    return ret;

}