When you write code, you often need to repeat actions multiple times. This is where iteration comes in. Iteration means repeating a set of instructions, and in programming, loops let you do this without writing the same code over and over. In PHP, the for loop is a powerful tool for automating repetitive tasks, such as processing lists, generating sequences, or performing calculations a set number of times. Understanding how to use the for loop will help you write cleaner, more efficient code.

This example uses a for loop to print the numbers 1 through 5. Let's break down how this works. The for loop has three main parts: initialization, condition, and increment. First, the variable '$i' is initialized to 1. Next, the loop checks the condition '$i <= 5'. If the condition is true, the code inside the loop runs. After each iteration, the increment '$i++' increases the value of '$i' by 1. The loop repeats this process until the condition is no longer true, which happens when '$i' becomes 6. This structure allows you to control exactly how many times the loop runs and what happens each time.

In this example, the for loop is used to calculate the sum of numbers from 1 to 10. This introduces the idea of accumulation—adding values together as the loop progresses. The variable '$sum' is initialized to 0 before the loop starts. Each time the loop runs, the current value of '$i' is added to '$sum'. It's essential to initialize the accumulator variable ('$sum') before the loop, or the result would be incorrect. This pattern is common when you need to total values, build strings, or collect data within a loop.