Guys I still dont get Unary operator

Unary operators change a single number or target and return a value. The unary operators can be used as prefix operators or postfix operators. Some uses of unary operators are to identify positive numbers (+) negative (-) numbers and to increment(++) or decrement (--) a numeric value.
Here are some examples from the Swift Programming language documents:

Increment operator (++) and decrement operator (--) are shortcuts to increase or decrease the value of a numeric variable by 1.

Increment unary operator (++) var a=0 let b = ++a //a and b are now both equal to 1 due to ++ unary operator incrementing a by 1.

Decrement operator (--) var i = 10 --i // i = 9

If the unary operator is written BEFORE the variable it increments the variable BEFORE returning its value. If the operator is written AFTER the variable it increments the variable AFTER returning it's value. You can check out the Swift Programming language document of examples.

You can toggle the sign of the numeric value using the unary minus and plus operators.

Unary Minus Operator: let three = 3 let minusThree = -three //minusThree equals -3 let plusThree = -minusThree //plusThree equals 3, or "minus minus three"

The Unary Plus Operator doesn't actually do anything but it can provide symmetry in your code. The unary plus operator just returns the value it operates on. let minusSix = -6 let alsoMinusSix = +minusSix //alsoMinusSix equals -6