swift-operators-1

swiftoperators1.swift

// Math Operators
// Addition
var a = 10 + 20      // a is equal to 30 (10 + 20 = 30)
// Subtraction
var s = 100 - 75     // s is equal to 25 (100 - 75 = 25)
// Multiplication - we use * to multiply
var m = 10 * 15      // m is equal to 150 (10 x 15 = 150)
// Division - we use / to divide
var d = 100 / 50     // d is equal to 2 (100 ÷ 50 = 2)
/* 
 *note about division, it is easy to divide numbers and end up
 * with a float value (decimal value)
 * if you do not make the variable strongly typed you will end up
 * with an an Integer value (6 / 5 = 1)
 *   (e.g. var a: Float = 50 / 100  or  var a: Double = 50 /100)
 */

// Comparison operators
// Greater than
var gt = 2 > 1      // gt is equal to true (2 is bigger)
// Less than
var lt = 2 < 1      // lt is equal to false (2 is not smaller)
// Equal to - we use double equal signs to determine equality
//            we use a single equal sign for assignment
var eq = (2 == 2)   // eq is equal to true (2 is equal to 2)
// Greater than or equal to
var gtEq = (2 >= 2) // gtEq is equal to true (2 is equal to 2)
// Less than or equal to
var ltEq = (2 <= 3) // ltEq is equal to true
// Unary Operators (1 operand, binary is two operands as above)
// Not equal
var notEq = (2 != 3) // notEq is true
// Minus operator (there is a plus but it does not change anything)
var minus = -(-100) // minus is 100
// Logical Operators
// And operator - this and that must be true
var andOp = (true && 3 == 3)  // andOp equals true
// Or operator - this or that must be true
var orOp = (true || false).  // orOp equals true
// Not operator - reverses the result of a boolean evaluation
var isRaining = !true // isRaining is false