## Loops

Loops are used to run code over and over again. There are two types of loops:
• `for` loops - run a predetermined number of times
• `while` loops - run as long as a specified condition is true
Example of a for loop that runs 5 times:
```for i in range(5):
print(i)
# prints 0, 1, 2, 3, 4
```
Make sure to indent each line in the body of the loop. The variable `i` starts at 0, and increases by 1 on each iteration of the loop. The loop variable is often called `i`, but it can be called anything. The `range` function determines the number of times the loop runs. If one argument is passed, the loop variable goes from 0 to one less than the argument value. If two arguments are passed, the loop variable goes from the first argument value to one less than the second argument value.
Example of a while loop that runs as long as the command is not "quit":
```count = 0
command = ""
while command != "quit":
command = input("Enter a command: ")
count = count + 1
print(f"Loop has repeated {count} times.")
```
The loop runs as long as the condition `command != "quit"` is true. Once the user types "quit", the loop stops. To have a loop run forever, simply put `True` for the condition.

### Exercise 1 of 5

Write the start of the loop to print the numbers 0 through 9.
```# start of loop here
print(number)
```

### Exercise 2 of 5

Write the start of the loop to print the even numbers from 20 to 30.
```# start of loop here
print(i * 2)
```

### Exercise 3 of 5

Write the start of the loop to print random numbers until it prints 5.
```import random
number = 0
# start of loop here
number = random.randint(0, 9)
print(number)
```

### Exercise 4 of 5

Write the start of the loop to run until the user enters the command "quit".
```command = ""
# start of loop here
command = input("Enter a command: ")
```

```# start of loop here