null pointer

基本解釋

NULL is defined simply as a null pointer (0) because the null pointer is invalid as a pointer anyway.
NULL 被簡(jiǎn)單地定義為一個(gè)空指針（0），因?yàn)闊o(wú)論如何空指針都不是合法的指針。
Instead of defining a separate class for empty lists, it represents empty lists by putting a null pointer in both fields.
它在兩個(gè)域中都放置一個(gè)空指針來(lái)表示空鏈表，而不是為空鏈表定義一個(gè)單獨(dú)的類。
Unlike, for example, a class-cast exception, a null-pointer exception says nothing about what was expected instead of the null pointer.
例如，不像一個(gè)類轉(zhuǎn)型異常，空指針異常不給出它所需要的內(nèi)容的任何信息，只有一個(gè)空指針。

null -pointer dereference 空指針引用;個(gè)空指針引用
Null pointer assignment 無(wú)效的斷點(diǎn)分配;無(wú)效的斷點(diǎn)分派;無(wú)效的續(xù)點(diǎn)分派;無(wú)效的續(xù)點(diǎn)調(diào)配
null pointer value [計(jì)]零指示字值;空指針值;零指示字值英語(yǔ);翻譯
null pointer vsalue 空指針值
Null pointer givement 有效的斷點(diǎn)分配