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Can you declare a variable inside a while loop?
You can put a variable declaration in the test expression of a while loop. What you cannot do is put a declaration statement in other expressions.
Do While loop with variable?
Unlike other kinds of control statement, the braces in a do-while are required. In the above example, the variable input was declared before the loop. Due to scope rules, variables declared within the block cannot be used within the condition. Normally, the statements controlled by the loop must affect the condition.
Can I declare variable in while loop C++?
declaring variables in a while loop question You are correct in your assumption. myvec will essentially go out of scope at the end of each iteration of the loop. If you don’t want to declare it outside of the loop, you could make it static so it won’t be destroyed when it goes out of scope.
Does a while loop have its own scope?
when while loop is executed – the variable i defined inside while is having local scope, where as the variable under (i > 3) follows the global variable, and doesn’t refer to local scope.
What is a loop variable?
In computer programming, a loop variable is a variable that is set in order to execute some iterations of a “for” loop or other live structure. A loop variable is a classical fixture in programming that helps computers to handle repeated instructions.
DO FOR loops have scope?
The explanation is that a for loop has an own scope for every iteration. We can see that well by looking at the code that is generated if we transpile our code down to ES5 using Babel: In line 8, we can see that every loop iteration is represented by invoking a function with the loop variable i .
Can a variable be declared outside of a while loop?
The scope of local variables should always be the smallest possible. In your example I presume str is not used outside of the while loop, otherwise you would not be asking the question, because declaring it inside the while loop would not be an option, since it would not compile.
Do you declare STR inside or outside the loop?
So, since str is not used outside the loop, the smallest possible scope for str is within the while loop. So, the answer is emphatically that str absolutely ought to be declared within the while loop.
Where do you declare a variable in Java?
But in the name of best coding practice it is recommended to declare the variable in the smallest possible scope (in this example it is inside the loop, as this is the only place where the variable is used). Declaring objects in the smallest scope improve readability.
Is it possible to declare height inside the DO / WHILE LOOP?
Yes and no. Yes, it is possible, and perfectly permissible to declare height inside the do/while loop, but there’s a problem. If you only wanted to use height inside the loop, it’s fine. But, the height var would cease to exist when the code exits the loop, so you couldn’t use it later. It’s a matter of variable scope.