Question

What are the 3 different loops?

Answer 1

In programming, there are three main types of loops used to repeat a set of instructions:

1. **For Loop**:
   - This loop is used when you know in advance how many times you want to execute a statement or a block of statements.
   - Syntax (in most languages like Python, C++, etc.):
     ```python
     for i in range(start, end, step):
         # code to execute
     ```
   - Example:
     ```python
     for i in range(1, 6):
         print(i)
     ```
     This prints numbers from 1 to 5.

2. **While Loop**:
   - A while loop repeats a block of code as long as a condition is true. It's useful when you don’t know beforehand how many times the loop will run, and you need to repeat until a specific condition is met.
   - Syntax:
     ```python
     while condition:
         # code to execute
     ```
   - Example:
     ```python
     i = 1
     while i <= 5:
         print(i)
         i += 1
     ```
     This also prints numbers from 1 to 5.

3. **Do-While Loop** (not in all languages, like Python, but present in languages like C/C++):
   - This loop executes the code at least once before checking the condition. After that, it repeats as long as the condition is true.
   - Syntax (in languages like C/C++):
     ```c
     do {
         // code to execute
     } while (condition);
     ```
   - Example:
     ```c
     int i = 1;
     do {
         printf("%d\n", i);
         i++;
     } while (i <= 5);
     ```
     This prints numbers from 1 to 5, but the code inside the loop runs at least once, even if the condition is false initially.

So, the three loops are:

- **For loop**: When the number of iterations is known.
- **While loop**: When the number of iterations is not known and depends on a condition.
- **Do-while loop**: Similar to while but ensures the loop runs at least once.

Let me know if you need examples in any specific language!