Question

Write a for loop that displays all of the odd numbers, 1 through 49.

Short answer

Question: Write a for loop that iterates through numbers 1 to 49 and displays only the odd numbers.

Step-by-step solution

Initialize the loop

To start the loop, use the for statement and define the iteration variable (let's call it "i") and the range of numbers we want the loop to go through (1 to 49). In Python, the range() function takes an end value and generates numbers up to but not including that end value. So, for iterating through 1 to 49, we will use range(1, 50).

Check if the number is odd

To check if a number is odd, we can use the modulo operator (%). The modulo operator returns the remainder of the division of the number by another number. If a number is odd, it will have a remainder of 1 when divided by 2.

Print the odd numbers

Once we have checked if a number is odd, we can print it. To do that, we can use the "print()" function in Python. Now we can put it all together in the for loop. Here is the complete solution using python: ```python for i in range(1, 50): if i % 2 == 1: print(i) ```

Key concepts

Iterating Over Odd Numbers

Understanding how to iterate over a specific set of numbers, like odd numbers, is a fundamental skill in programming. In Python, when tasked with displaying all odd numbers within a certain range, one efficient way to do so is by using a for loop. The loop executes a block of code repeatedly, based on the conditions set.

Let's say we need to list the odd numbers from 1 to 49. We can leverage the for loop, which iterates over a sequence of numbers produced by the range function. Within this loop, we specifically target odd numbers by checking if the current number has a remainder when divided by 2. This is a common approach to filtering out even numbers, allowing the loop to 'skip' them and only execute the print statement for the odd numbers. To emphasize the simplicity, we can think of the loop as a filtering mechanism, where only numbers that pass the 'odd' test are displayed.

Understanding the Modulo Operator

The modulo operator, represented by the symbol %, is a tool that returns the remainder of a division between two numbers. In Python, it's quite common to use the modulo operator when we need to determine whether a number is even or odd. If we take any integer and divide it by 2, the remainder will be 0 if it's even, and 1 if it's odd.

For example, in our task to print odd numbers from 1 through 49, we use i % 2 == 1 as a condition. Here's what happens: for each number i in our range, we calculate i divided by 2 and look at the remainder; if it's 1 (i is odd), we execute the print() function. This simple yet powerful operation allows us to effortlessly sift through numbers and pick out those with the desired property—in this case, being odd.

Utilizing the Range Function

The range function in Python is an invaluable tool when we need to generate a series of numbers within a specific interval. When using it in a for loop, it determines which numbers to loop over. The signature of this function is range(start, stop[, step]).

In our odd numbers example, range(1, 50) generates a sequence from 1 to 49, as it stops right before the stop parameter. The start parameter defines where the sequence begins, and the optional step parameter indicates the increment between numbers in the sequence, which defaults to 1 when omitted.

Importantly, when inputting the values for start and stop, it's crucial to remember that stop is exclusive. If we want to include the number 49 in our iteration, we set the stop value to 50.