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Does while loop check condition first?
A while loop evaluates its condition before the first iteration, and inbetween each subsequent iteration. The condition is never evaluated inside the loop body. It checks it before running again (first time, after first run and so on). You have to break or whole chunk of code will run.
Which loop first check the condition and then starts execution?
Contrast with the while loop, which tests the condition before the code within the block is executed, the do-while loop is an exit-condition loop. This means that the code must always be executed first and then the expression or test condition is evaluated. If it is true, the code executes the body of the loop again.
When to use the ” while ” loop in programming?
The “While” Loop. A “While”. Loop is used to repeat a specific block of code an unknown number of times, until a condition is met. For example, if we want to ask a user for a number between 1 and 10, we don’t know how many times the user may enter a larger number, so we keep asking “while the number is not between 1 and 10”.
How is a while statement evaluated in a loop?
while (condition) { statements; } It is an entry-controlled loop. In while loop, a condition is evaluated before processing a body of the loop. If a condition is true then and only then the body of a loop is executed.
When is a condition checked in an exit controlled loop?
In an exit controlled loop, a condition is checked after executing the body of a loop. It is also called as a post-checking loop. The control conditions must be well defined and specified otherwise the loop will execute an infinite number of times.
Is the while loop executed in a subshell?
Here’s a complete test program: The while loop is executed in a subshell. So any changes you do to the variable will not be available once the subshell exits. Instead you can use a here string to re-write the while loop to be in the main shell process; only echo -e $lines will run in a subshell: