Infinite Loops

This lesson explains how infinite loops might arise in a while loop using an example.

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What are Infinite Loops #

One common programming mistake is to create an infinite loop. An infinite loop refers to a loop, which under certain valid (or at least plausible) input, will never exit.

Note: Beginner programmers” should be careful to examine all the possible inputs into a loop to ensure that for each such set of inputs, there is an exit condition that will eventually be reached.

Compilers, debuggers, and other programming tools can only help the programmer so far in detecting infinite loops.

Note: In the sufficiently general case, it is not possible to automatically detect an infinite loop. This is known as the halting problem.

While the halting problem is not solvable in the fully general case, it is possible to determine whether a loop will halt for some specific cases.

Example of Infinite loop #

Down below is an example of an infinite loop.

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<?php
$a = 1;
// the while condition will always be met as it will always return true
while ($a)
{
    echo "Infinite loop\n";
}
?>

Please review the code above and explain what’s happening. Our AI mentor will analyze your response and provide assistance!

What's happening in the above code!

Now that you know all there is to know about the for loop, let’s solve a quiz in the next lesson.