询问一些概念，这个程序咋读取的，可以解析一下吗

char str[100]
英文字母     if(str[i]>='a'&& str[i]<='z'||str[i]>='A'&& str[i]<='Z')
数字            else if(str[i]>='0'&&str[i]<='9')
空格            else if(str[i]==' ')
其他            else

如果答案对您有帮助，还请采纳，谢谢！

#include <stdio.h>
#include <string.h>

int main(void)
{
    char data [] = "aefa23are4e1 q32?>@#$%&4aEdf";

    int count_char, count_num, count_black, count_else;
    count_char = count_num = count_black = count_else = 0;

    for (int i=0; i < strlen(data); i++){
        if((data[i] >= 'a' && data[i] <= 'z') || (data[i] >= 'A' && data[i] <= 'Z')){
            count_char ++;
        }
        else if(data[i] == ' ' ){
            count_black ++;
        }
        else if(data[i] >= '0' && data[i] <= '9'){
            count_num ++;
        }
        else{
            count_else ++;
        }
   }
    printf("字符个数 %d\n",count_char);
    printf("数字个数 %d\n",count_num);
    printf("空格个数 %d\n",count_black);
    printf("其他个数 %d\n",count_else);
}