{"id":2588,"date":"2026-02-02T12:13:31","date_gmt":"2026-02-02T12:13:31","guid":{"rendered":"https:\/\/demo.materiamedica.net\/demo6\/?p=2588"},"modified":"2026-02-02T12:13:31","modified_gmt":"2026-02-02T12:13:31","slug":"chapter-4-swift-statements","status":"publish","type":"post","link":"https:\/\/demo.materiamedica.net\/demo6\/chapter-4-swift-statements\/","title":{"rendered":"Chapter 4: Swift Statements"},"content":{"rendered":"1. What is a \u201cstatement\u201d in Swift?<\/h3>\n
A statement<\/strong> is any complete instruction that Swift can execute. It usually ends with a semicolon ; \u2014 but in Swift you almost never need to write ; at the end<\/strong> (only when you put multiple statements on one line).<\/p>\nExamples of statements:<\/p>\n
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print(\"Hello\") \/\/ expression statement\r\nlet name = \"Priya\" \/\/ declaration statement\r\nreturn 42 \/\/ control statement\r\nbreak \/\/ control statement<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n2. Most Common Category: Simple Expression Statements<\/h3>\n
These are the statements you write most often \u2014 they evaluate an expression and (usually) do something with the result.<\/p>\n
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\/\/ Most common\r\nprint(\"Namaste!\") \/\/ calls function\r\nscore += 10 \/\/ assignment + arithmetic\r\nnames.append(\"Aarav\") \/\/ method call\r\nisRaining = false \/\/ assignment\r\ntemperature -= 2.5 \/\/ compound assignment\r\nuser?.updateProfile() \/\/ optional chaining<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nImportant note<\/strong>: Even a function call that returns something is a valid statement \u2014 you can ignore the return value.<\/p>\n\n
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Swift<\/div>\n
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_ = loadUserData() \/\/ I call it but I don't use the result<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n3. Declaration Statements (let, var, func, struct, enum, class\u2026)<\/h3>\n
These introduce new names into your code.<\/p>\n
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Swift<\/div>\n
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\/\/ Variables and constants\r\nlet maximumUsers = 100\r\nvar currentUsers = 0\r\n\r\n\/\/ Computed property inside struct\/class\r\nvar fullName: String {\r\n return firstName + \" \" + lastName\r\n}\r\n\r\n\/\/ Typealias\r\ntypealias UserID = Int64\r\n\r\n\/\/ Function declaration\r\nfunc calculateTax(income: Double) -> Double {\r\n return income * 0.18\r\n}\r\n\r\n\/\/ Structure \/ Class \/ Enum\r\nstruct Point {\r\n var x: Double\r\n var y: Double\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n4. Control Flow Statements \u2013 if, guard, switch<\/h3>\n
These decide which code runs.<\/p>\n
4.1 if \u2013 else if \u2013 else<\/h4>\n\n
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Swift<\/div>\n
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let temperature = 34\r\n\r\nif temperature > 38 {\r\n print(\"Heatwave warning!\")\r\n} else if temperature > 32 {\r\n print(\"Very hot day\")\r\n} else if temperature > 25 {\r\n print(\"Typical summer\")\r\n} else {\r\n print(\"Quite pleasant\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nOne-line if (sometimes used):<\/strong><\/p>\n\n
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Swift<\/div>\n
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if isLoggedIn { showDashboard() }<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n4.2 guard \u2013 very popular in Swift<\/h4>\n
guard is used for early exit<\/strong> \u2014 it makes code much easier to read.<\/p>\n\n
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Swift<\/div>\n
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func processOrder(items: [String]?, address: String?) {\r\n guard let items else {\r\n print(\"No items selected\")\r\n return\r\n }\r\n \r\n guard !items.isEmpty else {\r\n print(\"Cart is empty\")\r\n return\r\n }\r\n \r\n guard let address, !address.isEmpty else {\r\n print(\"Delivery address required\")\r\n return\r\n }\r\n \r\n print(\"Order is valid \u2014 proceeding to payment\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nKey difference<\/strong>:<\/p>\n\n- if let = keep going deeper (nested)<\/li>\n
- guard let = exit early \u2192 flatter, cleaner code<\/li>\n<\/ul>\n
4.3 switch \u2013 very powerful in Swift<\/h4>\n\n
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Swift<\/div>\n
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let grade = \"A+\"\r\n\r\nswitch grade {\r\ncase \"A\", \"A+\":\r\n print(\"Excellent!\")\r\ncase \"B\", \"B+\":\r\n print(\"Good\")\r\ncase \"C\":\r\n print(\"Average\")\r\ncase \"D\", \"F\":\r\n print(\"Needs improvement\")\r\ndefault:\r\n print(\"Invalid grade\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nAdvanced switch examples you see often:<\/strong><\/p>\n\n
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Swift<\/div>\n
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\/\/ Ranges\r\nlet statusCode = 404\r\n\r\nswitch statusCode {\r\ncase 200..<300:\r\n print(\"Success\")\r\ncase 400..<500:\r\n print(\"Client error\")\r\ncase 500...:\r\n print(\"Server error\")\r\ndefault:\r\n print(\"Unknown\")\r\n}\r\n\r\n\/\/ Matching enums (very common)\r\nenum Direction {\r\n case north, south, east, west\r\n}\r\n\r\nlet heading = Direction.north\r\n\r\nswitch heading {\r\ncase .north: print(\"\u2191\")\r\ncase .south: print(\"\u2193\")\r\ncase .east: print(\"\u2192\")\r\ncase .west: print(\"\u2190\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n5. Loop Statements<\/h3>\n5.1 for-in loop (most common)<\/h4>\n\n
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Swift<\/div>\n
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let cities = [\"Hyderabad\", \"Bengaluru\", \"Chennai\", \"Pune\"]\r\n\r\nfor city in cities {\r\n print(\"I love \\(city)!\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nWith index:<\/p>\n
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Swift<\/div>\n
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for (index, city) in cities.enumerated() {\r\n print(\"\\(index + 1). \\(city)\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n5.2 for with range<\/h4>\n\n
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Swift<\/div>\n
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for number in 1...5 {\r\n print(number) \/\/ 1 2 3 4 5\r\n}\r\n\r\nfor i in 0..<10 {\r\n print(i) \/\/ 0 to 9\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n5.3 while & repeat-while<\/h4>\n\n
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Swift<\/div>\n
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var count = 0\r\n\r\nwhile count < 5 {\r\n print(\"Count is \\(count)\")\r\n count += 1\r\n}\r\n\r\nvar diceRoll: Int\r\n\r\nrepeat {\r\n diceRoll = Int.random(in: 1...6)\r\n print(\"Rolled: \\(diceRoll)\")\r\n} while diceRoll != 6<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n6. Transfer Statements \u2013 control flow jumps<\/h3>\n
These change the normal flow.<\/p>\n
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\n\n\n| Statement<\/th>\n | What it does<\/th>\n | Where you use it most<\/th>\n<\/tr>\n<\/thead>\n |
\n\n| break<\/td>\n | Exit the nearest loop \/ switch<\/td>\n | Loops, switch<\/td>\n<\/tr>\n |
\n| continue<\/td>\n | Skip to next iteration of loop<\/td>\n | Loops<\/td>\n<\/tr>\n |
\n| fallthrough<\/td>\n | Continue to next case in switch<\/td>\n | Rare, intentional<\/td>\n<\/tr>\n |
\n| return<\/td>\n | Exit function \/ closure<\/td>\n | Functions<\/td>\n<\/tr>\n |
\n| throw<\/td>\n | Throw an error<\/td>\n | Throwing functions<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n Examples:<\/p>\n \n \n \n Swift<\/div>\n \n for number in 1...10 {\r\n if number == 7 { continue } \/\/ skip 7\r\n if number == 9 { break } \/\/ stop at 9\r\n print(number)\r\n}\r\n\r\n\/\/ fallthrough (rare but useful sometimes)\r\nlet value = 2\r\n\r\nswitch value {\r\ncase 1:\r\n print(\"One\")\r\n fallthrough\r\ncase 2:\r\n print(\"Two\")\r\ndefault:\r\n print(\"Other\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n7. do \u2013 catch (Error Handling Statements)<\/h3>\n\n \n \n Swift<\/div>\n \n enum NetworkError: Error {\r\n case timeout\r\n case invalidURL\r\n}\r\n\r\nfunc fetchData() throws {\r\n throw NetworkError.timeout\r\n}\r\n\r\ndo {\r\n try fetchData()\r\n print(\"Success\")\r\n} catch NetworkError.timeout {\r\n print(\"Request timed out\")\r\n} catch {\r\n print(\"Unknown error: \\(error)\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nModern short version:<\/p>\n \n \n \n Swift<\/div>\n \n if let data = try? fetchData() {\r\n \/\/ success\r\n} else {\r\n \/\/ failed\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nQuick Reference Table \u2013 Most Important Statements<\/h3>\n\n \n \n\n\n| Kind<\/th>\n | Statement Example<\/th>\n | Most Common Use Case<\/th>\n<\/tr>\n<\/thead>\n | \n\n| Expression<\/td>\n | print(“Hi”)<\/td>\n | Doing work, calling functions<\/td>\n<\/tr>\n | \n| Declaration<\/td>\n | let name = “Amit”<\/td>\n | Creating variables, functions, types<\/td>\n<\/tr>\n | \n| if<\/td>\n | if age >= 18 { … }<\/td>\n | Simple conditions<\/td>\n<\/tr>\n | \n| guard<\/td>\n | guard let name else { return }<\/td>\n | Early exit \/ input validation<\/td>\n<\/tr>\n | \n| switch<\/td>\n | switch status { case 200..<300: … }<\/td>\n | Multiple conditions, enums, ranges<\/td>\n<\/tr>\n | \n| for-in<\/td>\n | for item in array { … }<\/td>\n | Iterating collections<\/td>\n<\/tr>\n | \n| while \/ repeat-while<\/td>\n | while condition { … }<\/td>\n | Unknown number of iterations<\/td>\n<\/tr>\n | \n| return<\/td>\n | return result<\/td>\n | Exit function with value<\/td>\n<\/tr>\n | \n| break \/ continue<\/td>\n | if condition { break }<\/td>\n | Early exit from loop<\/td>\n<\/tr>\n | \n| do-catch<\/td>\n | do { try … } catch { … }<\/td>\n | Handling errors<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<\/div>\n Small Practice \u2013 Combine several statements<\/h3>\nTry writing this in a playground:<\/p>\n \n \n \n Swift<\/div>\n \n let temperatures = [28, 34, 41, 19, 25]\r\n\r\nfor (index, temp) in temperatures.enumerated() {\r\n print(\"\\(index + 1). Today's temperature: \\(temp)\u00b0C\")\r\n \r\n guard temp <= 40 else {\r\n print(\" \u2192 Heat alert! Stay hydrated!\")\r\n continue\r\n }\r\n \r\n switch temp {\r\n case ..<20:\r\n print(\" \u2192 It's chilly \u2014 wear a jacket\")\r\n case 20..<30:\r\n print(\" \u2192 Nice weather\")\r\n case 30...:\r\n print(\" \u2192 Hot day\")\r\n default:\r\n break\r\n }\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\nNext topic you want to explore deeply?<\/p>\n \n- More about switch<\/strong> (pattern matching, associated values)<\/li>\n
- Closures<\/strong> (very important statement style)<\/li>\n
- defer<\/strong> statement (cleanup code)<\/li>\n
- throwing functions & do-try-catch<\/strong> in more detail<\/li>\n
- async\/await<\/strong> statements (modern concurrency)<\/li>\n<\/ul>\n
Just tell me what you want next \u2014 we\u2019ll keep going in the same detailed way \ud83d\ude0a<\/p>\n","protected":false},"excerpt":{"rendered":" 1. What is a \u201cstatement\u201d in Swift? A statement is any complete instruction that Swift can execute. It usually ends with a semicolon ; \u2014 but in Swift you almost never need to write...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[76],"tags":[],"class_list":["post-2588","post","type-post","status-publish","format-standard","hentry","category-swift"],"_links":{"self":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2588","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/comments?post=2588"}],"version-history":[{"count":1,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2588\/revisions"}],"predecessor-version":[{"id":2589,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2588\/revisions\/2589"}],"wp:attachment":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/media?parent=2588"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/categories?post=2588"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/tags?post=2588"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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