Functions in Programming is a block of code that encapsulates a specific task or related group of tasks.

Functions are defined by a name, may have parameters and may return a value.

The main idea behind functions is to take a large program, break it into smaller, more manageable pieces (or functions), each of which accomplishes a specific task.

A function declaration tells the compiler about a function’s name, return type, and parameters.

1. declaration

                 // Function declaration
                function sum(a, b, c) {
                    return a + b + c;
                }

                

2. function call

                sum(5, 6, 7);
                

eg:

find area of defferent shapes

              //find area of Circle 
              var area = π × r2;
              //find area of Triangle 
              var area = ½ × b × h
              //find area of Square 
              var area = a2
              //find area of Rectangle  
              var area = l × w
              //find area of Parallelogram  
              var area = b × h
              //find area of Ellipse  
              var area = πab
              //find area of Circle2 
              var area = π × r2;
              //find area of Circle3 
              var area = π × r2;

              

the above code is rewritten using function

              function circle(){
                  var area = π × r2;
              }
              function triangle(){
                 var area = ½ × b × h
              }
              circle()
              circle()
              circle()
              triangle()

              

1. Modularity of code:

Functions in Programming help break down a program into smaller, manageable modules. Each function can be developed, tested, and debugged independently, making the overall program more organized and easier to understand.

2. Abstraction:

Functions in Programming allow programmers to abstract the details of a particular operation. Instead of dealing with the entire implementation, a programmer can use a function with a clear interface, relying on its functionality without needing to understand the internal complexities.

3. Code Reusability:

Functions in Programming enable the reuse of code by encapsulating a specific functionality. Once a function is defined, it can be called multiple times from different parts of the program, reducing redundancy and promoting efficient code maintenance. Functions can be called multiple times, reducing code duplication.

4. Code is easily maintainable 5. Testing and debugging