How to change a variable by "set value"
Hi there. By today I like to do an actually simple task, where I didn't succeed. I created a variable, which is shown in a textfield on my prototype. The variable has as a default value a number. On my prototype is a button, which should change the number by a formula. Let's say the default value of the number is 10 (set in the default field of the variable property window) and the button should add 15, the textfield in the prototype should show 25.
For the "On tap" event of the button I add the event "Set value" and added the following formula: ["variable_name" + "15"] – see the attached pic. Unluckily after simulating the prototype the value of the variable remains 10 – the "Set value" has no effect.
Has anybody an idea, how the formula can work?
To fake it by just changing the value to 25 is not an option – there will be later several buttons in the prototype which add or deduct values from the variable.