04 Loops and Iteration Free Online FlashCards

When does a `while` loop test its condition?

A `while` loop tests its condition before executing the body, so it may execute zero times.

What guarantees that a `do-while` body runs once?

A `do-while` loop executes its body first, then tests its condition, so the body runs at least once.

What three parts does a C++ `for` header combine?

A `for` header contains initialization, a condition, and an update expression.

What is the usual scope of a `for` initialization variable?

A variable declared in a `for` loop’s initialization normally has scope only within that loop.

What does `break` do inside nested loops?

`break` immediately terminates the innermost enclosing loop and continues with the first statement afterward.

What happens after `continue` in a `for` loop?

In a `for` loop, `continue` skips the rest of the body, then runs the update expression before testing the condition again.

Why can `continue` cause a `while` loop to become infinite?

In a `while` loop, update the condition’s control variable before `continue`; otherwise, the condition may never change and the loop may not terminate.

What is an accumulator used for?

An accumulator stores a running result; initialize it before the loop and update it during every relevant iteration.

What is a sentinel in input processing?

A sentinel is a special input value that signals the end of input and is usually not processed as ordinary data.

What is the purpose of a validation loop?

A validation loop repeatedly requests input until the value satisfies the required condition.

How many times does a nested grid body execute?

For a rectangular grid with `r` rows and `c` columns, the inner loop body executes $r \times c$ times.

What causes a loop to become infinite?

A loop can fail to terminate when its condition-control state never changes toward making the condition false.