The Gatekeeper

Classic programmed-learning exercises, refreshed for modern Java and presented in the current MrStyner.com portfolio style.

Modern Java noteThis archive has been refreshed for Java 25 LTS. Core language concepts remain useful, while outdated setup instructions and browser-era Java are labeled or replaced. Java 26 is the current feature release; Java 25 is used here as the stable teaching baseline.
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Answer:

count is: 1
count is: 3
count is: 5        after printing this, count is changed to 5+2=7
Done counting by two's.

The Gatekeeper

gatekeeper

The loop control variable count does not need to hit the limit exactly :

while ( count <= 6 ) 

In the above, the value 5 passed the test and the loop body executed. Then count was incremented to 7. Then 7 failed the test.

The condition part of a while is like a gatekeeper. It checks if execution is to be admitted into the loop body. It doesn't care how things came to be; if the test yields false, the loop body is skipped.

This is shown in the flowchart. Execution flows along the lines in the direction of the arrows. The diamond marked "Test Condition" represents the gatekeeper. If the condition tests true, execution enters the loop body. If the condition tests false, execution is not allowed into the loop body.

When the loop body is executed variables and other things are changed. Execution then returns to the top of the loop, where the gatekeeper again decides whether to let it enter the loop body.

QUESTION 3:

Say that the test condition is count <= 6 and that there are many statements in the loop body. If one of the statements in the middle of the loop body changes count to 12, does the loop body immediately stop execution? (Hint: look at the flow chart.)