{"id":2671,"date":"2026-02-05T09:50:18","date_gmt":"2026-02-05T09:50:18","guid":{"rendered":"https:\/\/demo.materiamedica.net\/demo6\/?p=2671"},"modified":"2026-02-05T09:50:18","modified_gmt":"2026-02-05T09:50:18","slug":"chapter-43-swift-if-else","status":"publish","type":"post","link":"https:\/\/demo.materiamedica.net\/demo6\/chapter-43-swift-if-else\/","title":{"rendered":"Chapter 43: Swift If…Else"},"content":{"rendered":"

1. What is if\u2026else?<\/h3>\n

if\u2026else is the most fundamental way<\/strong> to make decisions in code.<\/p>\n

It answers the question:<\/p>\n

\n

\u201cIf this condition is true, do this block of code. Otherwise (else), do something different (or do nothing).\u201d<\/p>\n<\/blockquote>\n

Basic structure:<\/p>\n

\n
\n
\n
Swift<\/div>\n
\n
if condition {\r\n    \/\/ code to run if condition is true\r\n} else {\r\n    \/\/ code to run if condition is false\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
The else part is optional<\/strong>.<\/p>\n
2. Very first examples \u2013 try these right now<\/h3>\n
\n
\n
\n
Swift<\/div>\n
\n
let temperature = 32\r\n\r\nif temperature > 30 {\r\n    print(\"It's really hot \ud83e\udd75\")\r\n} else {\r\n    print(\"The weather is nice \ud83c\udf24\ufe0f\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
\n
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\n
Swift<\/div>\n
\n
let age = 17\r\n\r\nif age >= 18 {\r\n    print(\"You can vote \u2713\")\r\n}\r\n\/\/ no else \u2192 do nothing if false<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
\n
\n
\n
Swift<\/div>\n
\n
let isRaining = true\r\n\r\nif isRaining {\r\n    print(\"Take umbrella \u2614\")\r\n} else {\r\n    print(\"Nice day for a walk \ud83c\udf1e\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
3. else if \u2014 checking multiple conditions<\/h3>\n
When you have more than two possibilities<\/strong>, use else if.<\/p>\n
\n
\n
\n
Swift<\/div>\n
\n
let temperature = 28\r\n\r\nif temperature > 35 {\r\n    print(\"Extreme heat warning! \ud83d\udd25\")\r\n} else if temperature > 30 {\r\n    print(\"Very hot day \u2600\ufe0f\")\r\n} else if temperature > 25 {\r\n    print(\"Warm and pleasant \ud83d\ude0a\")\r\n} else if temperature > 15 {\r\n    print(\"Cool weather \ud83e\udde5\")\r\n} else {\r\n    print(\"It's cold! \u2744\ufe0f\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
Important rules about else if:<\/strong><\/p>\n
    \n
  • Swift checks conditions from top to bottom<\/strong><\/li>\n
  • As soon as one condition is true<\/strong>, it runs that block and skips all the rest<\/strong><\/li>\n
  • You can have as many else if as you want<\/li>\n
  • The final else (optional) catches everything else<\/strong><\/li>\n<\/ul>\n
    4. Real-life examples \u2013 the kind of code you will actually write<\/h3>\n
    Example 1 \u2013 Simple login status<\/h4>\n
    \n
    \n
    \n
    Swift<\/div>\n
    \n
    let isLoggedIn = true\r\nlet hasPremium = false\r\n\r\nif isLoggedIn {\r\n    if hasPremium {\r\n        print(\"Welcome back, Premium member! \ud83c\udf96\ufe0f\")\r\n    } else {\r\n        print(\"Welcome back! Consider Premium for more features \u2728\")\r\n    }\r\n} else {\r\n    print(\"Please sign in to continue\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
    Example 2 \u2013 Form validation (very common in apps)<\/h4>\n
    \n
    \n
    \n
    Swift<\/div>\n
    \n
    let email = \"aarav@example.com\"\r\nlet password = \"Secure123!\"\r\nlet termsAccepted = true\r\n\r\nvar errors: [String] = []\r\n\r\nif email.isEmpty {\r\n    errors.append(\"Email is required\")\r\n} else if !email.contains(\"@\") || !email.contains(\".\") {\r\n    errors.append(\"Please enter a valid email\")\r\n}\r\n\r\nif password.isEmpty {\r\n    errors.append(\"Password is required\")\r\n} else if password.count < 8 {\r\n    errors.append(\"Password must be at least 8 characters\")\r\n}\r\n\r\nif !termsAccepted {\r\n    errors.append(\"You must accept the terms\")\r\n}\r\n\r\nif errors.isEmpty {\r\n    print(\"Form is valid \u2013 creating account\u2026\")\r\n} else {\r\n    print(\"Please fix the following errors:\")\r\n    for error in errors {\r\n        print(\"\u2022 \\(error)\")\r\n    }\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
    Example 3 \u2013 Temperature \/ weather advice<\/h4>\n
    \n
    \n
    \n
    Swift<\/div>\n
    \n
    let temperatureCelsius = 33.2\r\nlet isRaining = false\r\n\r\nif temperatureCelsius >= 38 {\r\n    print(\"Dangerous heat! Stay indoors \ud83c\udfe0\ud83d\udca7\")\r\n} else if temperatureCelsius >= 32 {\r\n    print(\"Very hot \u2014 drink lots of water \ud83e\udd64\")\r\n} else if temperatureCelsius >= 25 {\r\n    print(\"Warm day \u2014 light clothes \ud83d\ude0e\")\r\n} else if temperatureCelsius >= 15 {\r\n    print(\"Pleasant weather \u2014 perfect for a walk \ud83c\udf33\")\r\n} else {\r\n    print(\"It's cold \u2014 wear a jacket \ud83e\udde5\")\r\n}\r\n\r\nif isRaining {\r\n    print(\"Don't forget umbrella \u2614\")\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
    Example 4 \u2013 Score \/ grade system (very typical)<\/h4>\n
    \n
    \n
    \n
    Swift<\/div>\n
    \n
    let percentage = 82.5\r\n\r\nlet grade: String\r\n\r\nif percentage >= 90 {\r\n    grade = \"A+\"\r\n} else if percentage >= 80 {\r\n    grade = \"A\"\r\n} else if percentage >= 70 {\r\n    grade = \"B\"\r\n} else if percentage >= 60 {\r\n    grade = \"C\"\r\n} else if percentage >= 50 {\r\n    grade = \"D\"\r\n} else {\r\n    grade = \"F\"\r\n}\r\n\r\nprint(\"You scored \\(percentage)% \u2192 Grade: \\(grade)\")<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
    5. Important Details & Best Practices<\/h3>\n
    Detail 1 \u2013 Conditions must be Bool<\/h4>\n
    \n
    \n
    \n
    Swift<\/div>\n
    \n
    let age = 20\r\n\r\n\/\/ Correct\r\nif age >= 18 { \u2026 }\r\n\r\n\/\/ Wrong\r\nif age { \u2026 }           \/\/ \u274c Compile error \u2013 Int is not Bool<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
    Detail 2 \u2013 Prefer positive conditions when possible<\/h4>\n
    \n
    \n
    \n
    Swift<\/div>\n
    \n
    \/\/ Harder to read\r\nif !isLoggedIn { showLogin() }\r\n\r\n\/\/ Easier to read\r\nif isLoggedIn {\r\n    showDashboard()\r\n} else {\r\n    showLogin()\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
    Detail 3 \u2013 Avoid very deep nesting<\/h4>\n
    Bad (hard to read):<\/p>\n
    \n
    \n
    \n
    Swift<\/div>\n
    \n
    if user != nil {\r\n    if user!.isPremium {\r\n        if user!.hasSubscription {\r\n            \/\/ \u2026\r\n        }\r\n    }\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
    Better:<\/p>\n
    \n
    \n
    \n
    Swift<\/div>\n
    \n
    guard let user else { return }\r\nguard user.isPremium else { return }\r\nguard user.hasSubscription else { return }\r\n\/\/ happy path<\/code><\/pre>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
    6. Very Common Beginner Mistakes & Fixes<\/h3>\n
    \n
    \n\n\n\n\n\n\n\n\n\n
    Mistake<\/th>\nWrong code<\/th>\nCorrect \/ Better way<\/th>\nWhy?<\/th>\n<\/tr>\n<\/thead>\n
    Using = instead of ==<\/td>\nif age = 18 { \u2026 }<\/td>\nif age == 18 { \u2026 }<\/td>\n= is assignment \u2014 compile error here<\/td>\n<\/tr>\n
    Writing == true everywhere<\/td>\nif isAdult == true { \u2026 }<\/td>\nif isAdult { \u2026 }<\/td>\nCleaner & idiomatic<\/td>\n<\/tr>\n
    Forgetting else if chain order<\/td>\nif score >= 80 { “A” } else if score >= 90 { “A+” }<\/td>\nPut higher conditions first<\/td>\nFirst true condition wins<\/td>\n<\/tr>\n
    Deep nesting instead of guard\/early return<\/td>\nmany nested ifs<\/td>\nUse guard or early return<\/td>\nFlatter, easier to read code<\/td>\n<\/tr>\n
    Comparing optionals incorrectly<\/td>\nif optional == 10 { \u2026 }<\/td>\nif let value = optional, value == 10 { \u2026 }<\/td>\nDirect comparison with nil is usually wrong<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    <\/div>\n<\/div>\n<\/div>\n
    7. Quick Reference \u2013 if patterns you will use most<\/h3>\n
    \n
    \n\n\n\n\n\n\n\n\n\n
    Situation<\/th>\nRecommended pattern<\/th>\nExample<\/th>\n<\/tr>\n<\/thead>\n
    Simple yes\/no<\/td>\nif condition { \u2026 } else { \u2026 }<\/td>\nif isRaining { \u2026 } else { \u2026 }<\/td>\n<\/tr>\n
    Multiple ranges<\/td>\nif \u2026 else if \u2026 else if \u2026 else { \u2026 }<\/td>\ngrade \/ temperature checks<\/td>\n<\/tr>\n
    Early exit \/ validation<\/td>\nguard condition else { return }<\/td>\nguard let user else { return }<\/td>\n<\/tr>\n
    Optional unwrapping + check<\/td>\nif let value = optional, value > 10 { \u2026 }<\/td>\nSafe optional handling<\/td>\n<\/tr>\n
    Short one-liner<\/td>\nif condition { doSomething() }<\/td>\nif isLoading { showSpinner() }<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    <\/div>\n<\/div>\n<\/div>\n
    8. Small Practice \u2013 Try these<\/h3>\n
      \n
    1. Write code that prints different messages based on temperature:\n
        \n
      • \n
        \n
        35 \u2192 “Extreme heat”<\/p>\n<\/blockquote>\n<\/li>\n
      • 30\u202635 \u2192 “Very hot”<\/li>\n
      • 25\u202630 \u2192 “Warm”<\/li>\n
      • else \u2192 “Cool”<\/li>\n<\/ul>\n<\/li>\n
      • Create a simple login check:\n
          \n
        • if not logged in \u2192 “Please sign in”<\/li>\n
        • if logged in but not premium \u2192 “Welcome! Get Premium?”<\/li>\n
        • if premium \u2192 “Welcome Premium member!”<\/li>\n<\/ul>\n<\/li>\n
        • Write a mini grade calculator: marks \u2265 90 \u2192 “A+” 80\u201389 \u2192 “A” 70\u201379 \u2192 “B” 60\u201369 \u2192 “C” below 60 \u2192 “Fail”<\/li>\n<\/ol>\n
          Paste your code here if you want feedback or want to see cleaner versions!<\/p>\n
          What would you like to explore next?<\/p>\n
            \n
          • guard statement in depth (very important companion to if)<\/li>\n
          • switch statement (often cleaner than long if\u2026else if chains)<\/li>\n
          • Combining if with optionals<\/strong> (if let, if case let, etc.)<\/li>\n
          • if in SwiftUI<\/strong> (conditional views)<\/li>\n
          • Or move to another topic (loops, functions, arrays, optionals\u2026)<\/li>\n<\/ul>\n
            Just tell me \u2014 we\u2019ll continue in the same clear, patient, detailed style \ud83d\ude0a<\/p>\n","protected":false},"excerpt":{"rendered":"
            1. What is if\u2026else? if\u2026else is the most fundamental way to make decisions in code. It answers the question: \u201cIf this condition is true, do this block of code. Otherwise (else), do something different...<\/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-2671","post","type-post","status-publish","format-standard","hentry","category-swift"],"_links":{"self":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2671","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=2671"}],"version-history":[{"count":1,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2671\/revisions"}],"predecessor-version":[{"id":2672,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/posts\/2671\/revisions\/2672"}],"wp:attachment":[{"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/media?parent=2671"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/categories?post=2671"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/demo.materiamedica.net\/demo6\/wp-json\/wp\/v2\/tags?post=2671"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}