Arithmethic and Logical Expressions

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Arithmetic Expressions

One of the basic things you can do in a program is to evaluate arithmetic expressions.

float result = (1+2)-3*2/2;

The program will store the resulting value of this expression in a float variable result. Your programs are intelligent enough to perform the evaluation following the PEMDAS.

Shortcuts

i++; // i = i + 1, adds 1 to the value of the variable and stores it back to the variable
i--; // i = i - 1
i += 2; // i = i + 2, basically, 2 can be any number

Logical Expressions

The next basic and most common thing you should learn is to evaluate logical expressions.

|| for logical OR
&& for logical AND
! for negation (returns 0 for positive values, 1 otherwise)

Logical operations used to evaluate expressions.

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int gameOver = 1; int win = 0; if (gameOver && !win) { printf("Sorry, you lose!"); }

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int hasBeenKickedOut = 1; int isSuspended = 1; bool isNotGoingToSchool = hasBeenKickedOut || isSuspended;

I think that was my first time (if not, then one of the few times) I stored the resulting value of a logical expression in a variable. Usually it is used inside an if or else-if statement or as a return value of a function (your will know more about function later in this course).

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if (hasBeenKickedOut || isSuspended) { isNotGoingToSchool = 1; }

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