Write code that prints out all the numbers from 1 to 10 as a single string.
Solution
var str = ""
for num in 1...10 {
str += "\(num)"
}
print(str) // 12345678910Write code that prints out all the even numbers from 5 to 51 as a single string.
Solution
var str = ""
for num in 5...51 where num % 2 == 0 {
str += "\(num) "
}
print(str)
// 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50Write code that prints out every number ending in 4 between 1 and 60 as a single string.
Solution
var str = ""
for num in 1...60 where num % 10 == 4 {
str += "\(num) "
}
print(str)
// 4 14 24 34 44 54Print each character in the string "Hello world!"
Solution
let str = "Hello world!"
for char in str {
print(char)
}
/*
H
e
l
l
o
w
o
r
l
d
!
*/Print out the last character in the string below. You cannot use the Character literal "!" (i.e you must access myStringSeven's characters).
let myStringSeven = "Hello world!"
Solution
let myStringSeven = "Hello world!"
let lastCharIndex = myStringSeven.index(before: myStringSeven.endIndex)
print(myStringSeven[lastCharIndex]) // !You are given a string stored in the variable aString. Create new string named replacedString that contains the characters of the original string with all the occurrences of the character "e" replaced by "*".
var aString = "Replace the letter e with *"
// Your code hereExample:
Input:
let aString = "Replace the letter e with *"
Expected values:
replacedString = "R*plac* th* l*tt*r * with *"
Solution
let aString = "Replace the letter e with *"
var replacedString = ""
for char in aString {
if char == "e" {
replacedString += "*"
continue
}
replacedString.append(char)
}
print(replacedString) // R*plac* th* l*tt*r * with *You are given a string stored in variable aString. Create a new string called reverse that contains the original string in reverse order. Print the reversed string. You cannot used built-in reverse.
let aString = "this string has 29 characters"
var reverse = ""
// Your code hereExample:
Input:
let aString = "Hello"
Output:
"olleH"
Solution
let aString = "Hello"
var reverse = ""
for char in aString {
reverse = String(char) + reverse
}
print(reverse) // olleHYou are given a string stored in variable aString. Print true if aString is a palindrome, and false otherwise. A palindrome is a string which reads the same backward or forward.
let str1 = "anutforajaroftuna"
// Your code hereExample 1:
Input:
let str1 = "anutforajaroftuna"
Output:
true
Example 2:
Input:
let str2 = "Hello"
Output:
false
Solution
let str1 = "anutforajaroftuna"
let str2 = "Hello"
var reverse = ""
for char in str1 {
reverse = String(char) + reverse
}
print(reverse == str1) // trueYou are given a string stored in variable problem. Write code so that you print each word of the string on a new line.
let problem = "split this string into words and print them on separate lines"
// Your codeExample:
Input:
let problem ="split this string into words and print them on separate lines"
Output:
split
this
string
into
words
and
print
them
on
separate
linesSolution
let problem = "split this string into words and print them on separate lines"
let words = problem.split(separator: " ")
for word in words {
print(word)
}
/*
split
this
string
into
words
and
print
them
on
separate
lines
*/You are given a string stored in variable problem. Write code that prints the longest word in the string.
let problem = "find the longest word in the problem description"
// Your code hereExample:
Input:
let problem = "find the longest word in the problem description"
Output:
description
Hint: Keep track of the longest word you encounter and also keep track of its length.
Solution
let problem = "find the longest word in the problem description"
let words = problem.split(separator: " ")
var largestWord = ""
for word in words {
if word.count > largestWord.count {
largestWord = String(word)
}
}
print(largestWord) // descriptionGiven a string in English, create a tuple containing the number of vowels and consonants.
let vowels = "aeiou"
let consonants = "bcdfghjklmnpqrstvwxyz"
let input = "Count how many vowels I have!"Solution
let vowels = Set("aeiou")
let consonants = Set("bcdfghjklmnpqrstvwxyz")
let input = "Count how many vowels I have!"
var vowelsConsonantsCount: (vowels: Int, consonants: Int) = (0, 0)
for char in input.lowercased() {
if vowels.contains(char) {
vowelsConsonantsCount.vowels += 1
continue
}
if consonants.contains(char) {
vowelsConsonantsCount.consonants += 1
}
}
print(vowelsConsonantsCount)
// (vowels: 8, consonants: 13)Given a string of words separated by a " ". Write code that prints out the length of the last word.
If there is no last word print out "No last word".
Example:
Input: "How are you doing this Monday?"
Output: 7
Solution
let str = "How are you doing this Monday?"
let words = str.split(separator: " ")
if let lastWord = words.last {
print(lastWord.count) // 7
} else {
print("No last word")
}Given a string testString create a new variable called condensedString that has any consecutive spaces in testString replaced with a single space.
let testString = " How about thesespaces ? "
var condensedString = ""
// Output: " How about thesespaces ? "Solution
let testString = " How about thesespaces ? "
var condensedString = ""
var previousChar: Character = "*"
for char in testString {
if previousChar == " " && char == " " {
continue
}
condensedString.append(char)
previousChar = char
}
print(condensedString) // " How about thesespaces ? "Given a string with multiple words. Reverse the string word by word. You cannot use built-in reverese or swapAt.
Example:
Sample Input: "Swift is the best language"
Sample Output: "language best the is Swift"
Solution
let str = "Swift is the best language"
var words = str.split(separator: " ")
var reverseWords = [String]()
for (index, _) in words.enumerated() where index < words.count / 2 {
let temp = words[index]
words[index] = words[words.count - 1 - index]
words[words.count - 1 - index] = temp
}
print(words.joined(separator: " ")) // language best the is SwiftGiven a string with multiple words. Write code that prints how many of them are palindromes.
Note: Feel free to use functions if you are already familiar with them.
Example:
Sample Input: "danaerys dad cat civic bottle"
Sample Output: 2
Solution
func isPalindrome(_ inputStr: String) -> Bool {
var reverse = ""
for char in inputStr {
reverse = String(char) + reverse
}
return reverse == inputStr
}
let str = "danaerys dad cat civic bottle"
let words = str.split(separator: " ")
var palindromeCount = 0
for word in words {
if isPalindrome(String(word)) {
palindromeCount += 1
}
}
print(palindromeCount) // 2You are given a string representing an attendance record for a student. The record only contains the following three characters:
'A' : Absent.
'L' : Late.
'P' : Present.
If a student has more than one 'A' or more than 2 continuous 'L's that student should not be rewarded. Print true if student is to be rewarded and False if they shouldn't.
Example:
Sample Input: "PPALLP"
Sample Output: true
Solution
let attendance = "PPALLP"
var absentCount = 0, lateCount = 0
var previousChar: Character = "*"
var isRewarded = true
for char in attendance {
if char == "A" {
absentCount += 1
if absentCount > 1 {
isRewarded = false
break
}
}
if char == "L" {
lateCount += 1
if previousChar == "L" {
if lateCount > 2 {
isRewarded = false
break
}
}
} else {
lateCount = 0
}
previousChar = char
}
print(isRewarded) // truefunc awardAttendance(_ str: String) -> Bool {
if str.contains("LLL") || (str.filter { $0 == "A" }.count > 1) {
return false
}
return true
}Given a tuple with two strings. The first string is a ransom note, the second string being the characters from a magazine. Determine whether or not you can construct the ransom note using the characters from the magazine.
Each letter from the magazine can only be used once. You can assume all letters are lowercased.
Examples:
Sample Input1: ("a", "b")
Sample Output1: False
Sample Input2: ("aa", "aab")
Sample Output2: True
Solution
let note: (ransomNote: String, magazine: String) = ("aa", "aab")
var magazine = note.magazine
var canCreateRansomNote = true
for char in note.ransomNote {
if magazine.contains(char) {
if let index = magazine.firstIndex(of: char) {
magazine.remove(at: index)
}
} else {
canCreateRansomNote = false
break
}
}
print(canCreateRansomNote) // true