Do while false 的作用
Web使用代码块,代码块内定义变量,不用考虑变量重复问题. 当你的功能很复杂,变量很多你又不愿意增加一个函数的时候,使用do{}while(0);,将你的代码写在里面,里面可以定义变量而不用考虑变量名会同函数之前或者之后的重复。 WebOct 14, 2024 · do{}while(false): 在工作中我们能经常发现有人写 do{}while(false) 这样的代码,初看时让人迷惑不解,按照上面的语法 do{}while(false) 这样 do{} 里面的代码只会执行一次的啊,那么问题来了,为什么要这样写?. 试想,我们在工作中是不是经常会遇到一种情况:第二个判断需要依赖第一个判断的结果,甚至 ...
Do while false 的作用
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Web它的格式是:. do. {. 语句; } while (表达式); 注意,while 后面的分号千万不能省略。. do…while 和 while 的执行过程非常相似,唯一的区别是:“do…while 是先执行一次循环体,然后再判别表达式”。. 当表达式为“真”时,返回重新执行循环体,如此反复,直到 ... WebThe "do {} while (false)" with a "break" can be used to skip to the end of the code block should something that would normally warrant an exception be encountered in the loop. I have also sen this construct used in shops where the "single return per function" …
WebJan 24, 2024 · In this article. The do-while statement lets you repeat a statement or compound statement until a specified expression becomes false.. Syntax. iteration-statement: do statement while (expression) ;. The expression in a do-while statement is evaluated after the body of the loop is executed. Therefore, the body of the loop is … WebJan 12, 2011 · The reason for this weird practice in #define's is to encapsulate the different assignments within a loop that is executed exactly once, so one may use the macro like a function.
WebFeb 10, 2024 · 你只用do-while来实现循环? 太浪费了! 这篇文章讲解的知识点很小,但是在一些编程场合中非常适用,大家可以把这篇短文当做甜品来品味一下。 WebJan 12, 2024 · do while 语法: 众所周知,do while 循环是执行一遍do{} 里面的代码然后,再去while()判断条件是否为真,为真继续执行do{}里面的代码,否则就跳出循环。 当然我们也可以采用 break 跳出循环,也可以采用 continue 结束本次循环开始下一次循环。
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Web当然这里的例子可能不太恰当,没有体现出使用场合的必要性,即不用 do while false 也能实现同样的效果。其实这种看似怪异的写法,主要是用来取代函数作用域内 goto(JavaScript 中没有 goto 关键字)的作用,再不使用 goto ... b what was the average speed during the fallWebJun 14, 2016 · Using this means that I can create localized variables that will go out of scope though just using brackets without the do { } while (false); does that as well. However I use the do while because I need the break; capability as well. I would consider using this style under some of the following conditions. If the business logic that is being ... cf 437WebJun 24, 2009 · 在C++中,有三种类型的循环语句:for, while, 和do...while, 但是在一般应用中作循环时, 我们可能用for和while要多一些,do...while相对不受重视。 但是,最近在读我们项目的代码时,却发现了do...while的一些十分聪明的用法,不是用来做循环,而是用作 … b what time is itWebFeb 19, 2016 · Explanation: W ( [1m;]'DCA'W (Zr1+rZ W Get one line from STDIN (evaluate it, if possible) ( [1m;] If not zero, go to the first index of lines of code (next line) and then end execution. 'DCA' Push character literals "ACD" to the stack. W Get another (the second) line from STDIN. ( If not zero, do the next instruction. cf437WebDec 10, 2014 · 在C++中,有三种类型的循环语句:for, while, 和do…while, 但是在一般应用中作循环时, 我们可能用for和while要多一些,do…while相对不受重视。但是我发现了do…while的一些十分聪明的用法,不是用来做循环,而是用作其他来提高代码的健壮性。1. do…while(0)消除goto语句通常,如果在一个函数中开始要 ... b what u wanna b flacWebJul 5, 2014 · 参考:do{}while(0)只执行一次无意义?你可能真的没理解. 在嵌入式开发中,宏定义非常强大也非常便捷,如果正确使用可以让你的工作事半功倍。然而,在很多的C程序中,你可能会看到不是那么直接的比较特殊一点的宏定义,比如do{}while(0)。 cf435WebFeb 25, 2024 · Explanation. statement is always executed at least once, even if expression always yields false. If it should not execute in this case, a while or for loop may be used.. If the execution of the loop needs to be terminated at some point, a break statement can be used as terminating statement.. If the execution of the loop needs to be continued at the … bwha website