Re: [問題] 99年普考 指標問題
小弟淺見,按照答案,重新題目翻成簡單易懂的形式:
"p是一個指標,所存的為y變數的位址"
若答案選(A),就成了p指標所指之內容為y變數之值的複製.
茲舉範例如下:
int *p;
int y;
p = (int)malloc(sizeof(int));
y = 10;
*p = y; //這時*p = 10, y = 10
*p = 100; //這時*p = 100, y = 10
看到這邊,我們就知道,p並沒有指向y變數的位址,否則改動*p時,y也會跟著改
再來我們看(C)的作法:
int *p;
int y;
p = (int)malloc(sizeof(int));
y = 10;
p = &y; //這時*p = 10, y = 10
*p = 100; //這時*p = 100, y = 100
y值會因為改動*p而跟著變動,所以p的確指向y變數的位址.
以上為小弟的想法.
謬誤之處,還望各位前輩不吝指教,謝謝.
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