Edit fiddle - JSFiddle - Code Playground
Tue Apr 18 2023 13:41:24 GMT+0000 (Coordinated Universal Time)
Saved by @Sree #undefined
import UIKit
// Closures lesson // https://www.udemy// // //.com/course/intermediate-ios--advance-your-skills-xcode--swift-3/learn/lecture/6#notes
// Long way 1. Write a func eg. doMath() that takes in 2 ints and another func as a type eg. takes in 2 integers then performs the input func on it
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// 2. Then write a separate func that will be passed in. eg multiply
// 3. Call the first func and pass in the 2nd func
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// 4. Use a closure instead of passing in th func, by hitting enter at the func param part
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// Long way 1. Write a func eg. doMath() that takes in 2 ints and another func as a type eg. takes in 2 integers then performs the input func on it
func doMath(a: Int, b: Int, mathFunc: (Int, Int) -> Int) -> Int {
return mathFunc(a, b)
}
// 2. Then write a separate func that will be passed in. eg multiply
func multiply (c: Int, d: Int) -> Int {
return c * d
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}
// 3. Call the first func and pass in the 2nd func
print(doMath(a: 5, b: 6, mathFunc: multiply(c:d:)))
// 4. Use a closure instead of passing in th func, by hitting enter at the func param part
doMath(a: 4, b: 6) { a, b in
return a * b
}
print(doMath(a: 5, b: 5) { $0 * $1})
// Closure lesson Complete
// Higher Order funcs and typealias
// 1. Create an array of some stuff and name it
// 2. Write a func that takes the array and converts it to uppercase.
// 3. Write a func that takes the array and converts it to double
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// 4. Call both funcs and see results
// 5. Both of the above functions are doing pretty mych the same thing. Creat a higher order function
// that takes in the string array and also another func that tells what to do each thing in that string array
// 6. Call the func for uppercasing - use enter to get the closure format
// 7. Replace the innerworking of the uppercaseArray and doubleArray with the changeArray func
// 8. Use shorthand $0 and $1 using curly braces {}
// 9. TypeAlias - allows to take an existing type and turn it into something else. It makes it easier to refer to a particular func type. You can give a func a name without refering to the func type eg. typealias changeValue = (String) -> String, replace the params for the edit func wiht it
// 1. Create an array of some stuff and name it
let myFam = ["Sree", "Ajit", "Krish", "Gaurav"]
// 2. Write a func that takes the array and converts it to uppercase.
func uppercase(_ name: [String]) -> [String] {
var tempArray:[String] = []
for str in name {
tempArray.append(str.uppercased())
}
return tempArray
}
// 3. Write a func that takes the array and converts it to double
func doubleArray(_ name: [String]) -> [String] {
var tempArray:[String] = []
for str in name {
tempArray.append(str.uppercased() + str.uppercased())
}
return tempArray
}
// 4. Call both funcs and see results
uppercase(myFam)
doubleArray(myFam)
// 5.Both of the above functions are doing pretty mych the same thing. Creat a higher order function
// that takes in the string array and also another func that tells what to do each thing in that string array.
// Note that the func behavior is not specified in the func, it is specified at the time of calling it
func changeArray(name: [String], theEditFunc: changeArrayValueFuncType) -> [String] {
var tmpArray: [String] = []
for str in name {
tmpArray.append(theEditFunc(str))
}
return tmpArray
}
// 6. Call the func for uppercasing - use enter to get the closure format
print(changeArray(name: myFam) { $0.uppercased() })
changeArray(name: myFam) { (str) -> String in
return str.lowercased()
}
// 7. Replace the innerworking of the uppercaseArray and doubleArray with the changeArray func
func uppercase2(_ str: [String]) -> [String] {
return changeArray(name: str) { (string) -> String in
return string.uppercased()
}
}
func doubleArray2(_ name: [String]) -> [String] {
return changeArray(name: name) { (string) -> String in
return (string + string)
}
}
uppercase2(myFam)
doubleArray2(myFam)
// 8. Use shorthand $0 and $1 using curly braces {}
func doubleArray3(_ name: [String]) -> [String] {
return changeArray(name: name) { "Hey " + $0 }
}
doubleArray3(myFam)
// 9. TypeAlias - allows to take an existing type and turn it into something else. It makes it easier to refer to a particular func type. You can give a func a name without refering to the func type eg. typealias changeValue = (String) -> String, replace the params for the edit func wiht it
typealias changeArrayValueFuncType = (String) -> String
doubleArray3(myFam)
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