warning:#550-D:variable "a" was set but never usedint a;for(i=0;i

warning:#550-D:variable "a" was set but never usedint a;for(i=0;i
warning:#550-D:variable "a" was set but never used
int a;
for(i=0;i

warning:#550-D:variable "a" was set but never usedint a;for(i=0;i
虽然不懂这是什么,不过
变量也就只有“读取”和“写入”这两个操作
“被使用”应该指的是“读取”操作
比如
int b=a;
从a中读取数据负值给b
其实,我是感觉声明和负值的地方离那么远很奇怪……
反正循环里面又不用,为什么不到负值的时候才声明……