C++ for Loop –

In C++, the for loop is an entry-controlled loop that is mainly utilized to iterate a part of the program multiple times. If the number of iterations is fixed, it is recommended to use for loop than while or do-while loops.

Syntax:

The C++ for loop is the same as other languages, such as C and C#. We can initialize variables, check conditions, and increment/decrement values.

• Initialization: It initializes the variables and is executed only once.
• Condition Statement: The condition statement checks the given condition. If the condition is true, it executes the of for loop. If the condition is false, it terminates the for loop.
• Update Expression: After execution of the loop body, this expression increments or decrements the loop variable by 1.

Flowchart of for Loop:

As we can see in the flowchart, use the following steps to implement the for loop in C++:

Step 1: First, go to the for loop and initialize the variables and their values.

Step 2: Next, the control flow jumps to the condition statement.

Step 3: Here, the condition is tested:

• If the condition is true, it executes the loop body.
• If the condition is false, it terminates the loop body and moves to the next iteration.

Step 4: After that, it goes to the update expression, where it increases or decreases the value by 1, and then again, it goes to step 3 to check the condition.

Step 5: At the end, it exits from the loop and prints the output.

Simple C++ for Loop Example:

Let us take a simple example to print the numbers 1 to 10 using the C++ for loop.

Output:

1
2
3
4
5
6
7
8
9
10

Factorial Program using C++ for Loop:

Let us take another example to find the factorial of a given number using a for loop in C++.

Output:

Multiplication table program using for loop in C++

Let us take an example to print a multiplication table using for loop in C++.

Output:

Enter a Number: 4
4 * 1 = 4
4 * 2 = 8
4 * 3 = 12
4 * 4 = 16
4 * 5 = 20
4 * 6 = 24
4 * 7 = 28
4 * 8 = 32
4 * 9 = 36
4 * 10 = 40

C++ Nested for Loop

In C++, if we have a for loop inside another for loop, it is known as a nested for loop. The inner loop is completely executed when the outer loop executes.

It allows us to perform complex iterations by executing a for loop for every iteration of the outer for loop. Nested for loops are beneficial when working with multi-dimensional arrays or patterns.

Syntax:

It has the following syntax:

Flowchart of Nested for loop:

C++ Nested for Loop Example:

Let us take a simple example of a nested for loop in C++.

Output:

1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3

C++ Pyramid Program using Nested for Loop:

Let us take an example to print a pyramid pattern using nested for loop in C++.

Output:

Enter the Number of rows: 6
* 
* * 
* * * 
* * * * 
* * * * * 
* * * * * *

Explanation:

In this example, we have taken two for loops. Here, the first loop handles the number of rows, and the second loop handles the number of columns and prints the stars.

C++ Inverted Pyramid Program using Nested for Loop:

Let us take an example to print an inverted pyramid pattern using nested for loop in C++.

Output:

Enter the Number of rows: 5
* * * * * 
* * * * 
* * * 
* * 
*

Explanation:

In this example, we have taken two for loops. Here, the outer loop handles the number of rows, and the inner loop handles the number of stars per row.

C++ foreach Loop

The foreach loop is also known as the range-based for loop. It is mainly utilized to iterate over the elements of a container (such as list, array, vector, etc) in a simple way without performing initialization, increment/decrement, and testing. The ‘for’ keyword is utilized for the foreach loop in C++.

Syntax:

It has the following syntax:

In this syntax,

• Variable_name: It is a variable name that is provided to the elements stored in a container.
• Container_name: It is a variable name of a container of any type, including list, array, vector, and many others.

C++ Foreach Loop Example:

Let us take an example to illustrate the foreach loop in C++.

Output:

20 25 30 35 40

Explanation:

In this example, we have taken a vector library for using dynamic arrays. Next, we declare a vector of integers. After that, we use two for loops in this program. The first loop uses a reference to modify the vector elements, and the second loop prints the modified values.

C++ Infinite for Loop

In C++, if we remove the initialization, condition, and update expression, it will result in an infinite loop.

In other words, if we use a double semicolon in the for loop, it will be executed infinite times.

Syntax:

It has the following syntax:

C++ Infinite For Loop Example:

Let us take an example to illustrate the infinite for loop in C++.

Output:

Hello! Tpointtech 
Hello! Tpointtech 
Hello! Tpointtech
Hello! Tpointtech

Here, we need to press Ctrl+C to exit from the infinitive program.

C++ for Loop MCQs

1. In for loop, which of the following operators is utilized to separate expressions in C++?

1. Colon (:)
2. Semicolon (;)
3. Ampersand (&)
4. Comma (,)

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2. Which of the following options is the first expression of for loop in C++?

1. Condition
2. Increment/decrement
3. Initialization
4. None of the above

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3. What will be the output of the following code?

1. 1 2 3 4 5
2. 1 2 3 4 5 6
3. 1 2 3 4
4. 0 1 2 3 4 5

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4. What type of loop is the for loop in C++ programming?

1. Exit-controlled loop
2. Recursive loop
3. Infinite loop
4. Entry-controlled loop

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5. Can we utilize the multiple initialization and update expression in a for loop in C++?

1. Yes
2. Only in C
3. No
4. Only in while loops

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