您要查找的是不是：
- The state or quality of being null. 无效无效的状况或性质
- A constant, variable, function name, or expression. 一种常数、变量、函数名或表达式。
- The prices are variable, shop around by all means. 价格高低不一，所以一定要货比三家逐店选购。
- The temperature was a variable in the experiment. 在该实验中温度是个变量。
- The act of making null and void. 废除使 ... 作废和无效
- The special NULL value represents that a variable has no value. 特殊的NULL值表示一个变量没有值。
- When a variable is first declared, its value is set to NULL. 第一次声明变量时,其值设置为NULL。
- A finite increment in a variable. 变量增量变量的有限增量
- The speed of the toy boat is variable. 玩具船的速度是可变的。
- Although explicitly nulling variables should normally have no effect, there are also pathological examples where it could have a significant negative effect on performance. 虽然显式赋空变量一般应该没有影响,但总有一些反面的例子证明这样做会对性能产生巨大的负面影响。
- Winds are mainly light and variable. 风力较弱，风向多变。
- Staying on the subject of garbage collection, one really fascinating discussion concerned whether there was a performance advantage to explicitly nulling variables. 一谈到垃圾收集这个主题,总会涉及到这样一个吸引人的讨论,即显式地赋空变量是否有助于程序的性能。
- The contract was null and void because it was not signed. 这个合同无效，因为它尚未签字。
- A programmed time delay of variable duration. 暂停，展宽一种由程序设置的可变持续时间的时间延迟
- The court ruled that the claim was null and void. 法庭裁决此项要求无效。
- The marriage was declared null and void. 婚姻已宣告无效了。
- The null subset corresponds to the term 1. 空集则对应于常数项1。
- A null reference pointer was passed to the stub. 向占位程序传送了空的索引指针。
- null variable 零变量
- The agreement was declared null and void. 这个协议被宣布无效。
