What does = do?

What does = do?

• A. It adds 1 to the left-hand side
• B. It assigns the value on the right-hand side to the variable on the left-hand side
• C. It compares two values
• D. It subtracts values

Answer: (B)

The equals sign is the assignment operator in most programming languages. It takes the value produced by the expression on the right and stores it in the location specified on the left, which is usually a variable (and can sometimes be other writable targets like array elements or object properties). First the right-hand side is evaluated, then that result is placed into the left-hand side. For example, a = 10 assigns the value 10 to a. If you write a = b + 1, you compute b + 1 and then store that result in a. In many languages the assignment expression also yields the value you just assigned, so you can chain assignments or use it inside larger expressions, though some languages have restrictions. This is different from the equality check, which uses a comparison operator (like == or ===) to test whether two values are the same, rather than storing a value.

The equals sign is the assignment operator in most programming languages. It takes the value produced by the expression on the right and stores it in the location specified on the left, which is usually a variable (and can sometimes be other writable targets like array elements or object properties). First the right-hand side is evaluated, then that result is placed into the left-hand side. For example, a = 10 assigns the value 10 to a. If you write a = b + 1, you compute b + 1 and then store that result in a. In many languages the assignment expression also yields the value you just assigned, so you can chain assignments or use it inside larger expressions, though some languages have restrictions. This is different from the equality check, which uses a comparison operator (like == or ===) to test whether two values are the same, rather than storing a value.