3/5 = 0.6
1/4 = 0.25
repeating decimal
1/3 = 0.333…
0.3-(bar mean forever)
1/7 = 0.14..
1/4 + 0.32 = 0.57
place values
0.627 -> 6tenth, 2hundredths, 7thousandths
2.18 = 109 / 50
1/4 + 0.32 = 0.57 / 100
随机应变 ABCD: Always Be Coding and … : хороший
3/5 = 0.6
1/4 = 0.25
repeating decimal
1/3 = 0.333…
0.3-(bar mean forever)
1/7 = 0.14..
1/4 + 0.32 = 0.57
place values
0.627 -> 6tenth, 2hundredths, 7thousandths
2.18 = 109 / 50
1/4 + 0.32 = 0.57 / 100
what is a fraction?
fraction = part / whole
mixed number has whole number and fractions
1+5/8
common denominators!
8/8 – 3/8 = 5/8 keep denominator same
circumference 88, 28.25
diameter 28, 9
circumference/diameter 3.14, 3.14
π = 3.14
radius * 2 = diameter
c = π*d
d = 3, c = 9.42
Area = πr^2
3^2 = 9, base is three exponent
Exponents are powerful!
first power
3^1 = 3
dividing by the base
3^4
3^3
3^2 = 9
3^1 = 3
3^0 = 1
-1 * 4^2 = -4^2 = -16
(-4)^2 = 16
PEMDAS
parentheses, exponents, multiply, divide, add, subtract
more order of operations
6 / [4- (6-8)]+(-2)^3= -7
area of a square
l*l
l^2
Number Lines
– arrows on each end, zero, marks to indicate scale, positive negative direction
arrow, the lines extend on forever
infinity: goes on forever without limit
+ or –
infinity is the largest on positive
the truth about number line
absolute value: distance from zero, cannot be negative, |number|
sum: the result of adding number together
quatient: the result of division
associative property: +, *
create a project
add views
define layouts
integrate functions
connect ui to code
respond to events
func firstCharacter(of word: String) -> Character { return word[word.startIndex] } firstCharacter(of: "Mom")
import Fundation func placeFirstLetterLast(myString: String){ }
func placeFirstLetterLast (myString: String) -> String { var myString = myString myString.append(firstCharacter(of: myString)) return myString } func shortNameFromName(name: String) -> String { let lowercaseName = name.lowercaseString let vowelSet = CharacterSet(charactersIn: "aeiou") } shortNameFromName(name: "Nate") // shortNameFromName(name: "Talia") //
func lyricsForName(lyricsTemplate: String, fullName: String) -> String { let shortName = shortNameForName(name: fullName) let lyrics = lyricsTemplate .replacingOccurrences(of: "<FULL_NAME>", with: fullName) .replacingOccurrences(of: "<SHORT_NAME>", with: shortName) return lyrics }
The function print, min, max, and abs are a few examples of global functions. Check out a complete list of Swift’s global functions.
print("I'm a global function!") var initialPrice = 50 var bestOffer = 45 var finalPrice = min(bestOffer, initialPrice)
Anatomy of a function
func functionName (_ parameterName: parameterType) -> returnType { statements to execute return object }
func sumOfStrings(_ aBunchOfStrings: [String]) -> Int { let array = aBunchOfStrings var sum = 0 for string in array { if Int(string) != nil { let int intToAdd = Int(string)! sum += intToAdd } } return sum }
func reverse(_ string: String) -> String { var reversedString = "" for character in string.characters { reversedString = "\(character)" + reversedString } return reversedString }
func warmUp(temperature: Int) -> Int { return temperature + 10 } func firstChar(word: String) -> Character { return word[word.startIndex] } func concatenate(firstString: String, secondString secondString){ return firstString + secondString } func warmUp(temperature: Int) -> Int { return temperature + 10 } func firstCharacter(word: String) -> Character { return word[word.startIndex] } func concatenate(firstString: String, secondString: String)-> String { return firstString + secondString }
var lightSwitchOn: Bool = true var dimmer: Int = 7 var dimmerWithDecimals: Float = 3.14 var veryPreciseDimmer: Double = 3.14159265359 print(type(of: lightSwitchOn)) print(type(of: veryPreciseDimmer))
Bool Double
Double, Bool, String, Float
use let to declare a constant when we expect its value to remain the same
we expect let not change
let encouragement = "You can do it!" var personalizedEncouragement = "You can do it, Stephanie!" personalizedEncouragement = personalizedEncouragement.replacingOccurrences(of: "Stephanie", with: "Ryder") let birthYear = 2008 var currentYear = 2016 var age = currentYear - birthYear age = currentYear - birthYear
var word = "fortunate" word.contains("tuna") var password = "Mary had a little loris" var newPassword = password.replacingOccurences(of: "a" with "A")
import Foundation var didYouKnowString = "Did you know that the Swift String class comes with lots of useful methods?" var whisperString = "pass" + ", " + "\(didYouKnowString.lowercased())" var shoutString = "TODO: Make the shoutString here!"
import Foundation var forwardString = "stressed" var lottaLikes = "If like, you wanna learn Swift like, you should build lots of small apps, cuz it's like, a good way to practice."
import Glibc var nounArray = ["puppy", "laptop", "ocean", "app", "cow", "skateboard", "developer", "coffee", "moon"] var index1 = Int(random() % 9) var index2 = Int(random() % 9) var sentence = "The \(nounarray[6]) spilled her \(nounArray[7])." var sillySentence = "The \(nounArray[index1]) jumped over the \(nounArray[index2])." print(sentence) print(sillySentence)
var eString = "Meet me in St. Louis" for character in eString.characters { if character == "e" { print("found an e!") } else { } }
var eString = "Meet me in St. Louis" for character in eString.characters { if character == "e" { print("found an e!") } else { } } var theTruth = "Mony can buy me love." var characterCount = theTruth.characters.count var forwardString = "spoons" var charactersReversed = forwardString.characters.reversed() var backwardsString = String(charactersReversed) print(backwardsString)
found an e! found an e! found an e! snoops