Introduction

This style guide outlines the common coding conventions of the iOS Developers.

Spacing
Comments

Spacing

Indent must use 4 spaces. Be sure to set this preference in Xcode (defaults is 4 spaces).

Method braces and other braces (if/else/switch/while etc.) must open on the same line as the statement. Braces must close on a new line.

For example: Objective-c

  if (user.isHappy) {
      // Do something
  }
  else {
      // Do something else
  }

Swift

  if user.isHappy == true {
      // Do something
  }
  else {
      // Do something else
  }

Separate imports from the rest of your file by 1 space. Optionally group imports if there are many (but try to have less dependencies). Include frameworks first.

For example: Objective-c

  #import <AwesomeFramework/AwesomeFramework.h>
  #import <AnotherFramework/AnotherFramework.h>
  #import "SomeDependency.h"
  #import "SomeOtherDependency.h"
  @interface MyClass

Swift

  import AwesomeFramework
  import AnotherFramework
  class MyViewController: UIViewController {
      // class stuff here
  }

In Objective-C, use one empty line between class extension and implementation in .m file.

  @interface MyClass()
  // Properties - empty line above and below
  @end
  @implementation MyClass
  // Body - empty line above and below
  @end

When using pragma marks leave 1 newline before and after.

For example: Objective-c

  - (void)awakeFromNib {
      [super awakeFromNib];
      // something
  }
  #pragma mark - Config Cell
  - (void)configCell {
      // something
  }

Swift

   override func awakeFromNib() {
      super.awakeFromNib()
      // somthing
  }
  // MARK: -  Config Cell
  func configCell() {
      //something
  }

Prefer using auto-synthesis. But if necessary, @synthesize and @dynamic must each be declared on new lines in the implementation.
There should be exactly one blank line between methods to aid in visual clarity and organization.
Whitespace within methods should separate functionality, but often there should probably be new methods.
When doing math use a single space between operators. Unless that operator is unary in which case don’t use a space.
For example:
```
  index = index + 1;
  index++;
  index += 1;
  index--;
```

Colon-aligning method invocation should often be avoided. There are cases where a method signature may have >= 3 colons and colon-aligning makes the code more readable. Please do NOT however colon align methods containing blocks because Xcode’s indenting makes it illegible.

Good:

objective-c

  // blocks are easily readable
  [UIView animateWithDuration:1.0 animations:^{
      // something
  } completion:^(BOOL finished) {
      // something
  }];

swift

  UIView.animate(withDuration: 1.0, animations: {
      // something
  }, completion: { finished in
      // somthing
  })

**Bad:**
**objective-c**    
```obj-c
// colon-aligning makes the block indentation wacky and hard to read
[UIView animateWithDuration:1.0
                 animations:^{
                     // something
                 }
                 completion:^(BOOL finished) {
                    // something
                 }];
```
**swift**
```swift
UIView.animate(withDuration: 1.0, 
                 animations: {
                    // something
                 }, completion: { finished in
                    // somthing
                 })
```

Comments

When they are needed, comments should be used to explain why a particular piece of code does something. Any comments that are used must be kept up-to-date or deleted.
Avoid block comments inline with code, as the code should be as self-documenting as possible. Exception: This does not apply to those comments used to generate documentation.

Developing….

Introduction

Table of Contents

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Comments

References