Temporary Index for a while loop-CodePudding

I have a loop with an index. But the index jumps up and down from time to time, so a for loop is out of the question. But I still need the index. I just don't like the idea of having a temporary index in my function which I am only using for one loop. e.g.

...
int i = 0;

while( i < something)
{
  if(a)
    i  :
  else
    i--:
}

...

Can I make i temporary for the loop? Maybe something like this?

...
temporary (int i = 0)
{

  while( i < something)
  {
    if(a)
      i  :
    else
      i--:
  }
}
...

CodePudding user response：

You can use the for loop in order to achieve this. the variable i will live only inside the for loop scope.

for (int i = 0; i < something;;)
{
  if(a)
     i  :
  else
     i--:
  }
}

CodePudding user response：

You can limit the range of a variable by enclosing its declaration and its use within curly braces. It looks a litte bit strange, but it works fine.

Then your i variable can't be accessed outside of this scope as shown below (you will get a compilation error) :

MyMethod()
{
  // ... lots of code here

  { 
    int i=0;

    while( i < something)
    {
      if(a)
        i  ;
      else
        i--;
    }  
    i--; // ok
  } 

  i--; // error : The name 'i' does not exist in the current context

  // ... some more code here
}