写一个小写转换成大写的程序，编译不过去，大神帮菜鸟看看，谢谢呵呵。
#include<stdio.h>
#include<string.h>

void main()
{
    char array[64];
    gets(array);
    array = TestTransform(array);
    puts(array);

}

char TestTransform(char * pcarray)
{
    char * propcarray;
    propcarray = pcarray;
    while(*pcarray = '0')
    {
        if(*pcarray >= 'a'||*pcarray <= 'z')
        {
            *pcarray = *pcarray - 32;
            pcarray++;
        }
        else
        {
            *pcarray = *pcarray;
            pcarray++;
        }   
    }

    return(propcarray);
}

我忘了声明函数不过问题不是出在这

类型出现问题吧
TextTransform.c: In function ‘main’:
TextTransform.c:12:8: error: incompatible types when assigning to type ‘char[64]’ from type ‘char’
TextTransform.c: In function ‘TestTransform’:
TextTransform.c:35:2: warning: return makes integer from pointer without a cast [enabled by default]
怎么改