Difference between JavaScript Function Declaration and JavaScript Expression

JavaScript functions enable us to perform a variety of tasks, make crucial choices, perform computations, and even enhance the interactivity of our websites. We shall discover the distinction between "function expression" and "function declaration" in this post. Both use the term function, which is where they are comparable. The main distinction is that the function declaration has a function name, while the latter does not.

Declaration of Function

• A function is declared using a function keyword in a function declaration, also referred to as a function statement.
• A function name is required in the function declaration.
• Functions are stand-alone structures that are not grouped inside functional blocks, so function declarations do not require variable assignments.
• They run ahead of all other codes.
• The function in the function declaration is accessible Both before and after the function definition.

Syntax

The following syntax is used for function declaration.

Example:

The following example shows the javascript declaration for the arithmetic operation.

Output:

The output shows the function declaration and its operation in an anonymous way.

Function Expression

• Without the function name, a function expression is comparable to a function declaration.
• Variable assignments allow for the storage of function expressions.
• Function expressions load and run once the program interpreter gets to the code line.
• Only after the function definition is the function in the function expression accessible.

Syntax:

The following syntax is used for a function expression.

Example:

The following example shows the javascript expression.

Output:

The output shows the function expression in an anonymous way and its operation.

Comparison between Function Declaration and Expression

The following table compares the function declaration and expression.

Conclusion

The Javascript function declaration and expression are important for the different functions and their operation. The developer and student use the function declaration and expression according to functionality and requirements.