Difference between revisions of "Swift Live Reference"
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| Line 5: | Line 5: | ||
|exerciseID=1 | |exerciseID=1 | ||
|height=100 | |height=100 | ||
| | |language=swift | ||
|initialCode= | |initialCode= | ||
// single-line comments begin with two slashes | // single-line comments begin with two slashes | ||
| Line 14: | Line 14: | ||
|exerciseID=2 | |exerciseID=2 | ||
|height=100 | |height=100 | ||
| | |language=swift | ||
|initialCode= | |initialCode= | ||
/* multi-line comments begin with slash-star | /* multi-line comments begin with slash-star | ||
| Line 27: | Line 27: | ||
|exerciseID=3 | |exerciseID=3 | ||
|height=100 | |height=100 | ||
| | |language=swift | ||
|initialCode= | |initialCode= | ||
print("Hello, World!") | print("Hello, World!") | ||
| Line 36: | Line 36: | ||
|exerciseID=4 | |exerciseID=4 | ||
|height=100 | |height=100 | ||
| | |language=swift | ||
|initialCode= | |initialCode= | ||
print("to", "ease", "another's", "heartache", separator: "*") | print("to", "ease", "another's", "heartache", separator: "*") | ||
| Line 45: | Line 45: | ||
|exerciseID=5 | |exerciseID=5 | ||
|height=100 | |height=100 | ||
| | |language=swift | ||
|initialCode= | |initialCode= | ||
print("to", "ease", "another's", "heartache", separator: "*", terminator: "<>") | print("to", "ease", "another's", "heartache", separator: "*", terminator: "<>") | ||
| Line 64: | Line 64: | ||
|exerciseID=6 | |exerciseID=6 | ||
|height=100 | |height=100 | ||
| | |language=swift | ||
|initialCode= | |initialCode= | ||
let gravity = 9.81 // meters per second per second | let gravity = 9.81 // meters per second per second | ||
| Line 75: | Line 75: | ||
|exerciseID=7 | |exerciseID=7 | ||
|height=100 | |height=100 | ||
| | |language=swift | ||
|initialCode= | |initialCode= | ||
var currentTemperature = 23.1 // degrees celsius | var currentTemperature = 23.1 // degrees celsius | ||
| Line 89: | Line 89: | ||
|exerciseID=9 | |exerciseID=9 | ||
|height=100 | |height=100 | ||
| | |language=swift | ||
|initialCode= | |initialCode= | ||
var n = 7 | var n = 7 | ||
Revision as of 23:06, 23 January 2023
Comments[edit]
Comments are used by humans to document code for other humans. They have no effect on the program itself.
Single-line comments[edit]
Multi-line comments[edit]
Output[edit]
print[edit]
print with separator[edit]
print with terminator[edit]
Types[edit]
In Swift, it is customary to capitalize all types.
- Int
- A signed integer value type
- Float
- A single-precision, floating-point value type
- Double
- A double-precision, floating-point value type
- String
- A Unicode string value that is a collection of characters
Constant and Variable Declarations[edit]
Constant Declarations[edit]
Constants (named values which should never change) use the let keyword
Variable Declarations[edit]
Variables (named values which may change) use the var keyword
Control Structures[edit]
Control structures are used to alter the otherwise sequential flow of a program.
Conditionals[edit]
Conditionals are used to execute a segment of code based upon a condition being met.
if[edit]
else[edit]
if n < 10 {
print("n is less than 10")
} else {
print("n is not less than 10")
}
switch[edit]
switch n {
case 0:
print("n is zero")
case 1:
print("n is one")
default:
print("n is neither one nor zero")
}
Loops[edit]
Loops are used to repeat a segment of code until a condition is met.
for[edit]
for loops are helpful when the number of iterations is known.
// From zero up to but excluding ten
for n in 0 ..< 10 {
print(n)
}
// From one up to and including ten
for n in 1 ... 10 {
print(n)
}
while[edit]
while loops are helpful when the condition may initially be false and the statements should not be executed.
while n < 10 {
n += 1
}
repeat while[edit]
repeat while loops are helpful when the statements should be executed at least once.
repeat {
n += 1
} while n < 10
