Variable name

You can find a general overview of variables here.

Variables should all begin with a capital but have no capitalization after, unless it’s necessary by convention, e.g., proper nouns. They also should not end in a full stop, but can end with a question mark for a question, or ellipses if the value select completes the sentence (see more below).

Choosing the correct variable name is an important part of calculator design, as it is what the user interacts with most directly. Therefore the variable name should be as short as possible while still conveying all of the important information. For example, in the circle calculator, the name “The circle’s circumference” would be much too long. The name “Circumference” is much better, as the fact it is the circle’s is implicit. Remember, you can always use help texts to explain things.

Note

If you have to differentiate between the same variable applied to two different things, e.g., “A’s widths” & “B’s width”, it is generally better to place the distinction in the heading/group and leave the variable in its simple form, in this case “Width”. However, if the result doesn’t look good, e.g., you have many groups with only one entry, the former example will suffice.

Variable names can also be questions in specific circumstances. Questions are useful for creating a chatty tone, but should be limited to Yes/No questions or asking people what they want from the calculator, e.g., “What do you want to find?”. As above, these should be as brief as possible and end with a question mark.

You may also want to create a variable that is a sentence completed by the different options of a value select, e.g., “I want to find the… area/volume/height”. In this case, the variable should end with ellipses (unless the question is very long already and you’re looking for ways to drop characters).

There are often symbols associated with particular variables you may also want to display next to the variable name. In this case they should be displayed after the variable and surrounded by brackets, e.g, “Height (h)”. If your symbol already has brackets around it and adding additional ones would be confusing, then you can replace the brackets with a comma, space, then symbol. So “Concentration ([M])” is better as “Concentration, [M]”.

Note

You can use emojis in variables, subject to the normal emoji rules. There is not set guide here, just whatever looks the best!