Is it bad to have nested for loops?

Is it bad to have nested for loops?

Nested loops are frequently (but not always) bad practice, because they’re frequently (but not always) overkill for what you’re trying to do. In many cases, there’s a much faster and less wasteful way to accomplish the goal you’re trying to achieve.

What do nested for loops do?

When a loop is nested inside another loop, the inner loop runs many times inside the outer loop. In each iteration of the outer loop, the inner loop will be re-started. The inner loop must finish all of its iterations before the outer loop can continue to its next iteration.

What is nested loop with example?

The inner loop is nested inside the outer loop. Nested loops are useful when for each pass through the outer loop, you need to repeat some action on the data in the outer loop. For example, you read a file line by line and for each line you must count how many times the word “the” is found.

How many nested loops is too many?

The C language allows for up to 127 levels of nested blocks; like 640KB of RAM, that’s all anyone should ever need. In practice, if you find yourself nesting more than 4 or 5 levels deep, think about factoring some of those inner levels out to their own functions (or re-think your algorithm).

Can a for loop contain another for loop?

A for loop can contain any kind of statement in its body, including another for loop.

Is a loop that has no end?

An infinite loop is a sequence of instructions in a computer program which loops endlessly, either due to the loop having no terminating condition, having one that can never be met, or one that causes the loop to start over.

When to use nested for loops in Python?

You can use nested for loops to put a cap on the number of times you retry the operation. This is bascially the sam as @PierreAlex’s generator answer but without the extra function definition.

How does a nested iteration statement work in Java?

Nested iteration statements are iteration statements that appear in the body of another iteration statement. When a loop is nested inside another loop, the inner loop must complete all its iterations before the outer loop can continue.

How to repeat an iteration in a loop?

Repeat an iteration in loop if error occurs Ask Question Asked6 years, 7 months ago Active2 years, 5 months ago Viewed20k times 18 2 Is there a command such as breakand continuewhich could repeat recent iteration? For example, when exception is thrown.

How to do a while true loop in Python?

You could use a while True:loop inside the for-loop: for i in range(500): while True: try: conn = getConnection(url+str(i)) doSomething(conn) except Exception: # Replace Exception with something more specific. continue else: break or without the else::