Re: [問題] this 在什麼情況下會等於NULL??
※ 引述《bgcrwf (老王)》之銘言：
: 最近在看程式碼的時候 有看到一段搞不懂
: if (this) {
: // blah....
: } else {
: // blah....
: }
: 想請教各位
: 在什麼情況下程式會進到else這個區塊來呢??
: 想很久想不出來
: 謝謝
像這樣的情況就會是哩：
A *a = NULL ;
a->f() ;
這樣 a::f() 裡面拿到的 this 就是 NULL。
會這樣設計的原因，
可以參考一個叫做 "Null Pointer(Object) Pattern" 的手法。
--
To iterate is human, to recurse, divine.
遞迴只應天上有, 凡人該當用迴圈. L. Peter Deutsch
--
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