What distinguishes 'var' from 'const' in variable declarations?

What distinguishes 'var' from 'const' in variable declarations?

• A. 'var' allows for re-assignment, while 'const' does not
• B. 'var' is used for global variables, while 'const' is local
• C. 'var' can only be used in functions, while 'const' is for global scope
• D. 'var' requires initialization, while 'const' does not

Answer: (A)

The choice that highlights the distinction between 'var' and 'const' is that 'var' allows for re-assignment, while 'const' does not. This means that when you declare a variable using 'var', you can change its value later in the code. This flexibility makes 'var' suitable for scenarios where you need to update the variable's value throughout its lifecycle. In contrast, when you declare a variable with 'const', you create a constant reference to a value that cannot be changed. Once a value is assigned to a 'const' variable, trying to re-assign it will lead to an error. This property of 'const' is particularly useful for defining values that should remain constant throughout the execution of the program, such as configuration settings or fixed computation results. Using 'var' and 'const' appropriately helps maintain clarity and intent in your code, making it easier to understand how variables are meant to behave during execution.

The choice that highlights the distinction between 'var' and 'const' is that 'var' allows for re-assignment, while 'const' does not. This means that when you declare a variable using 'var', you can change its value later in the code. This flexibility makes 'var' suitable for scenarios where you need to update the variable's value throughout its lifecycle.

In contrast, when you declare a variable with 'const', you create a constant reference to a value that cannot be changed. Once a value is assigned to a 'const' variable, trying to re-assign it will lead to an error. This property of 'const' is particularly useful for defining values that should remain constant throughout the execution of the program, such as configuration settings or fixed computation results.

Using 'var' and 'const' appropriately helps maintain clarity and intent in your code, making it easier to understand how variables are meant to behave during execution.