用户工具

站点工具


en:reference:language:goto
no way to compare when less than two revisions


前一修订版
en:reference:language:goto [2023/06/07 04:23] (当前版本) – 外部编辑 127.0.0.1
行 1: 行 1:
 +====== goto ======
 +
 +
 +Transfers program flow to a labeled point in the program
 +===== Syntax =====
 +
 +label:
 +goto label; <nowiki>// sends program flow to the label</nowiki>
 +===== Tip =====
 +
 +The use of goto is discouraged in C programming, and some authors of C programming books claim that the goto statement is never necessary, but used judiciously, it can simplify certain programs. The reason that many programmers frown upon the use of goto is that with the unrestrained use of goto statements, it is easy to create a program with undefined program flow, which can never be debugged.
 +
 +
 +With that said, there are instances where a goto statement can come in handy, and simplify coding. One of these situations is to break out of deeply nested for loops, or if logic blocks, on a certain condition.
 +===== Example =====
 +<code cpp>
 +for(byte r = 0; r < 255; r++){
 +  for(byte g = 255; g > -1; g--){
 +    for(byte b = 0; b < 255; b++){
 +      if (analogRead(0) > 250){ 
 +        goto bailout;
 +      }
 +      // more statements ... 
 +    }
 +  }
 +}
 +bailout:
 +</code>
  
en/reference/language/goto.txt · 最后更改: 2023/06/07 04:23 由 127.0.0.1