Swift Introduction | Values, Variables, and Operations | Additional Basics

Separating Statements with Newlines or Semicolons

Swift statements are usually separated by line breaks. To write multiple statements on one line, separate them with semicolons (;).

a = 1; b = 2; c = 3

Comments with // or /* */

Swift supports two comment styles. Text after // is treated as a comment until the end of the line. Text between /* and */ is also treated as a comment.

Block comments can be nested.

/* comment is /* THIS! */ text. */

Grouping Variable Declarations and Assignments

When declaring several variables, it can be convenient to write them together.

var (variable1, variable2, ...) = (value1, value2, ...)

The values are assigned in order: value1 to variable1, value2 to variable2, and so on.

Preventing Overflow with &

When working with large numbers, pay attention to overflow and underflow. Overflow occurs when an integer exceeds the range supported by its type. Underflow occurs when a floating-point value falls outside its representable precision. Other calculation errors include division by zero.

When you intentionally want wrapping behavior instead of an error, add & to the operator.

var x = y & + 100000

Casting Values

Swift values have static types. To calculate with values of different types, cast one value to the other type with Type(value).

// Convert to an integer
123 + Int(45.67)
// Convert to text
"123"+ String(456)

These concepts cover the basics of values, variables, and operations. The next topic is control statements, a core part of programming syntax.