*:first-child {
margin-top: 0 !important; }
body > *:last-child {
margin-bottom: 0 !important; }

a {
color: #4183C4; }
a.absent {
color: #cc0000; }
a.anchor {
display: block;
padding-left: 30px;
margin-left: -30px;
cursor: pointer;
position: absolute;
top: 0;
left: 0;
bottom: 0; }

h1, h2, h3, h4, h5, h6 {
margin: 20px 0 10px;
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
cursor: text;
position: relative; }

h1:hover a.anchor, h2:hover a.anchor, h3:hover a.anchor, h4:hover a.anchor, h5:hover a.anchor, h6:hover a.anchor {
background: url(data:image/png;base64,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) no-repeat 10px center;
text-decoration: none; }

h1 tt, h1 code {
font-size: inherit; }

h2 tt, h2 code {
font-size: inherit; }

h3 tt, h3 code {
font-size: inherit; }

h4 tt, h4 code {
font-size: inherit; }

h5 tt, h5 code {
font-size: inherit; }

h6 tt, h6 code {
font-size: inherit; }

h1 {
font-size: 28px;
color: black; }

h2 {
font-size: 24px;
border-bottom: 1px solid #cccccc;
color: black; }

h3 {
font-size: 18px; }

h4 {
font-size: 16px; }

h5 {
font-size: 14px; }

h6 {
color: #777777;
font-size: 14px; }

p, blockquote, ul, ol, dl, li, table, pre {
margin: 15px 0; }

hr {
background: transparent url(data:image/png;base64,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) repeat-x 0 0;
border: 0 none;
color: #cccccc;
height: 4px;
padding: 0;
}

body > h2:first-child {
margin-top: 0;
padding-top: 0; }
body > h1:first-child {
margin-top: 0;
padding-top: 0; }
body > h1:first-child + h2 {
margin-top: 0;
padding-top: 0; }
body > h3:first-child, body > h4:first-child, body > h5:first-child, body > h6:first-child {
margin-top: 0;
padding-top: 0; }

a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0; }

h1 p, h2 p, h3 p, h4 p, h5 p, h6 p {
margin-top: 0; }

li p.first {
display: inline-block; }
li {
margin: 0; }
ul, ol {
padding-left: 30px; }

ul :first-child, ol :first-child {
margin-top: 0; }

dl {
padding: 0; }
dl dt {
font-size: 14px;
font-weight: bold;
font-style: italic;
padding: 0;
margin: 15px 0 5px; }
dl dt:first-child {
padding: 0; }
dl dt > :first-child {
margin-top: 0; }
dl dt > :last-child {
margin-bottom: 0; }
dl dd {
margin: 0 0 15px;
padding: 0 15px; }
dl dd > :first-child {
margin-top: 0; }
dl dd > :last-child {
margin-bottom: 0; }

blockquote {
border-left: 4px solid #dddddd;
padding: 0 15px;
color: #777777; }
blockquote > :first-child {
margin-top: 0; }
blockquote > :last-child {
margin-bottom: 0; }

table {
padding: 0;border-collapse: collapse; }
table tr {
border-top: 1px solid #cccccc;
background-color: white;
margin: 0;
padding: 0; }
table tr:nth-child(2n) {
background-color: #f8f8f8; }
table tr th {
font-weight: bold;
border: 1px solid #cccccc;
margin: 0;
padding: 6px 13px; }
table tr td {
border: 1px solid #cccccc;
margin: 0;
padding: 6px 13px; }
table tr th :first-child, table tr td :first-child {
margin-top: 0; }
table tr th :last-child, table tr td :last-child {
margin-bottom: 0; }

img {
max-width: 100%; }

span.frame {
display: block;
overflow: hidden; }
span.frame > span {
border: 1px solid #dddddd;
display: block;
float: left;
overflow: hidden;
margin: 13px 0 0;
padding: 7px;
width: auto; }
span.frame span img {
display: block;
float: left; }
span.frame span span {
clear: both;
color: #333333;
display: block;
padding: 5px 0 0; }
span.align-center {
display: block;
overflow: hidden;
clear: both; }
span.align-center > span {
display: block;
overflow: hidden;
margin: 13px auto 0;
text-align: center; }
span.align-center span img {
margin: 0 auto;
text-align: center; }
span.align-right {
display: block;
overflow: hidden;
clear: both; }
span.align-right > span {
display: block;
overflow: hidden;
margin: 13px 0 0;
text-align: right; }
span.align-right span img {
margin: 0;
text-align: right; }
span.float-left {
display: block;
margin-right: 13px;
overflow: hidden;
float: left; }
span.float-left span {
margin: 13px 0 0; }
span.float-right {
display: block;
margin-left: 13px;
overflow: hidden;
float: right; }
span.float-right > span {
display: block;
overflow: hidden;
margin: 13px auto 0;
text-align: right; }

code, tt {
margin: 0 2px;
padding: 0 5px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px; }

pre code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent; }

.highlight pre {
background-color: #f8f8f8;
border: 1px solid #cccccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px; }

pre {
background-color: #f8f8f8;
border: 1px solid #cccccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px; }
pre code, pre tt {
background-color: transparent;
border: none; }

sup {
font-size: 0.83em;
vertical-align: super;
line-height: 0;
}
* {
-webkit-print-color-adjust: exact;
}
@media screen and (min-width: 914px) {
body {
width: 854px;
margin:0 auto;
}
}
@media print {
table, pre {
page-break-inside: avoid;
}
pre {
word-wrap: break-word;
}
}
-->

NSMutableArray基本概念

本小节知识点:

【理解】NSMutableArray介绍
【理解】NSMutableArray基本用法
【理解】NSMutableArray 错误用法

1.NSMutableArray介绍

什么是NSMutableArray
- NSMutableArray是NSArray的子类
- NSArray是不可变的,一旦初始化完毕后,它里面的内容就永远是固定的, 不能删除里面的元素, 也不能再往里面添加元素
- NSMutableArray是可变的,随时可以往里面添加\更改\删除元素

2.NSMutableArray基本用法

创建空数组

NSMutableArray *arr = [NSMutableArray array];

创建数组,并且指定长度为5,此时也是空数组

NSMutableArray *arr2 = [[NSMutableArray alloc] initWithCapacity:5];

创建一个数组,包含两个元素

NSMutableArray *arr3 = [NSMutableArray arrayWithObjects:@"1",@"2", nil];

调用对象方法创建数组

NSMutableArray *arr4 = [[NSMutableArray alloc] initWithObjects:@"1",@"2", nil];

- (void)addObject:(id)object;
- 添加一个元素
- (void)addObjectsFromArray:(NSArray *)array;
- 添加otherArray的全部元素到当前数组中
- (void)insertObject:(id)anObject atIndex:(NSUInteger)index;
- 在index位置插入一个元素
- (void)removeLastObject;
- 删除最后一个元素
- (void)removeAllObjects;
- 删除所有的元素
- (void)removeObjectAtIndex:(NSUInteger)index;
- 删除index位置的元素
- (void)removeObject:(id)object;
- 删除特定的元素
- (void)removeObjectsInRange:(NSRange)range;
- 删除range范围内的所有元素
- (void)replaceObjectAtIndex:(NSUInteger)index withObject:(id)anObject;
- 用anObject替换index位置对应的元素
- (void)exchangeObjectAtIndex:(NSUInteger)idx1 withObjectAtIndex:(NSUInteger)idx2;
- 交换idx1和idx2位置的元素

3.NSMutableArray 错误用法

不可以使用@[]创建可变数组

NSMutableArray *array = @[@"lnj", @"lmj", @"jjj"];

// 报错, 本质还是不可变数组

[array addObject:@“Peter”];

*:first-child {
margin-top: 0 !important; }
body > *:last-child {
margin-bottom: 0 !important; }

a {
color: #4183C4; }
a.absent {
color: #cc0000; }
a.anchor {
display: block;
padding-left: 30px;
margin-left: -30px;
cursor: pointer;
position: absolute;
top: 0;
left: 0;
bottom: 0; }

h1, h2, h3, h4, h5, h6 {
margin: 20px 0 10px;
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
cursor: text;
position: relative; }

h1 tt, h1 code {
font-size: inherit; }

h2 tt, h2 code {
font-size: inherit; }

h3 tt, h3 code {
font-size: inherit; }

h4 tt, h4 code {
font-size: inherit; }

h5 tt, h5 code {
font-size: inherit; }

h6 tt, h6 code {
font-size: inherit; }

h1 {
font-size: 28px;
color: black; }

h2 {
font-size: 24px;
border-bottom: 1px solid #cccccc;
color: black; }

h3 {
font-size: 18px; }

h4 {
font-size: 16px; }

h5 {
font-size: 14px; }

h6 {
color: #777777;
font-size: 14px; }

p, blockquote, ul, ol, dl, li, table, pre {
margin: 15px 0; }

a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0; }

h1 p, h2 p, h3 p, h4 p, h5 p, h6 p {
margin-top: 0; }

li p.first {
display: inline-block; }
li {
margin: 0; }
ul, ol {
padding-left: 30px; }

ul :first-child, ol :first-child {
margin-top: 0; }

blockquote {
border-left: 4px solid #dddddd;
padding: 0 15px;
color: #777777; }
blockquote > :first-child {
margin-top: 0; }
blockquote > :last-child {
margin-bottom: 0; }

img {
max-width: 100%; }

code, tt {
margin: 0 2px;
padding: 0 5px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px; }

pre code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent; }

.highlight pre {
background-color: #f8f8f8;
border: 1px solid #cccccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px; }

NSDictionary基本概念

本小节知识点:

【理解】NSDictionar基本概念
【理解】NSDictionary的创建
【理解】NSDictionary的遍历
【理解】NSDictionary文件操作

1.NSDictionar基本概念

什么是NSDictionary
- NSDictionary翻译过来叫做”字典”
- 日常生活中,“字典”的作用:通过一个拼音或者汉字,就能找到对应的详细解释
- NSDictionary的作用类似:通过一个key,就能找到对应的value
- NSDictionary是不可变的, 一旦初始化完毕, 里面的内容就无法修改

2.NSDictionary的创建

+ (instancetype)dictionary;

+ (instancetype)dictionaryWithObject:(id)object forKey:(id <NSCopying>)key;

+ (instancetype)dictionaryWithObjectsAndKeys:(id)firstObject, ...;

+ (id)dictionaryWithContentsOfFile:(NSString *)path;

+ (id)dictionaryWithContentsOfURL:(NSURL *)url;

NSDictionary创建简写
- 以前 objc NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"lnj", @"name", @"12345678", @"phone", @"天朝", @"address", nil];
- 现在 objc NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};
NSDictionary获取元素简写
- 以前 objc [dict objectForKey:@"name”];
- 现在 objc dict[@"name”];
键值对集合的特点
- 字典存储的时候,必须是"键值对"的方式来存储(同时键不要重复)
- 键值对中存储的数据是"无序的".
- 键值对集合可以根据键, 快速获取数据.

3.NSDictionary的遍历

- (NSUInteger)count;
- 返回字典的键值对数目
- (id)objectForKey:(id)aKey;
- 根据key取出value
快速遍历

    NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};

    for (NSString *key in dict) {

        NSLog(@"key = %@, value = %@", key, dict[key]);

    }

Block遍历

    [dict enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) {

        NSLog(@"key = %@, value = %@", key, obj);

    }];

4.NSDictionary文件操作

将字典写入文件中
- - (BOOL)writeToFile:(NSString *)path atomically:(BOOL)useAuxiliaryFile;
- - (BOOL)writeToURL:(NSURL *)url atomically:(BOOL)atomically;
- 存结果是xml文件格式,但苹果官方推荐为plist后缀。
示例

    NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};

    BOOL flag = [dict writeToFile:@"/Users/LNJ/Desktop/dict.plist" atomically:YES];

    NSLog(@"flag = %i", flag);

从文件中读取字典

NSDictionary *newDict = [NSDictionary dictionaryWithContentsOfFile:@"/Users/LNJ/Desktop/dict.plist"];

    NSLog(@"newDict = %@", newDict);

*:first-child {
margin-top: 0 !important; }
body > *:last-child {
margin-bottom: 0 !important; }

a {
color: #4183C4; }
a.absent {
color: #cc0000; }
a.anchor {
display: block;
padding-left: 30px;
margin-left: -30px;
cursor: pointer;
position: absolute;
top: 0;
left: 0;
bottom: 0; }

h1, h2, h3, h4, h5, h6 {
margin: 20px 0 10px;
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
cursor: text;
position: relative; }

h1 tt, h1 code {
font-size: inherit; }

h2 tt, h2 code {
font-size: inherit; }

h3 tt, h3 code {
font-size: inherit; }

h4 tt, h4 code {
font-size: inherit; }

h5 tt, h5 code {
font-size: inherit; }

h6 tt, h6 code {
font-size: inherit; }

h1 {
font-size: 28px;
color: black; }

h2 {
font-size: 24px;
border-bottom: 1px solid #cccccc;
color: black; }

h3 {
font-size: 18px; }

h4 {
font-size: 16px; }

h5 {
font-size: 14px; }

h6 {
color: #777777;
font-size: 14px; }

p, blockquote, ul, ol, dl, li, table, pre {
margin: 15px 0; }

a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0; }

h1 p, h2 p, h3 p, h4 p, h5 p, h6 p {
margin-top: 0; }

li p.first {
display: inline-block; }
li {
margin: 0; }
ul, ol {
padding-left: 30px; }

ul :first-child, ol :first-child {
margin-top: 0; }

blockquote {
border-left: 4px solid #dddddd;
padding: 0 15px;
color: #777777; }
blockquote > :first-child {
margin-top: 0; }
blockquote > :last-child {
margin-bottom: 0; }

img {
max-width: 100%; }

code, tt {
margin: 0 2px;
padding: 0 5px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px; }

pre code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent; }

.highlight pre {
background-color: #f8f8f8;
border: 1px solid #cccccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px; }

NSMutableDictionary基本概念

本小节知识点:

【理解】NSMutableDictionary 基本概念
【理解】NSMutableDictionary 常用方法
【理解】NSMutableDictionary 简写
【理解】NSDictionary和NSArray对比

1.NSMutableDictionary 基本概念

什么是NSMutableDictionary
- NSMutableDictionary是NSDictionary的子类
- NSDictionary是不可变的,一旦初始化完毕后,它里面的内容就永远是固定的,不能删除里面的元素, 也不能再往里面添加元素
- NSMutableDictionary是可变的,随时可以往里面添加\更改\删除元素

2.NSMutableDictionary的常见操作

- (void)setObject:(id)anObject forKey:(id )aKey;
- 添加一个键值对(会把aKey之前对应的值给替换掉)
- (void)removeObjectForKey:(id)aKey;
- 通过aKey删除对应的value
- (void)removeAllObjects;
- 删除所有的键值对

3.NSMutableDictionary的简写

设置键值对
- 以前 objc [dict setObject:@"Jack" forKey:@"name”];
- 现在 objc dict[@"name"] = @"Jack";

4.NSDictionary和NSArray对比

NSArray和NSDictionary的区别
- NSArray是有序的,NSDictionary是无序的
- NSArray是通过下标访问元素,NSDictionary是通过key访问元素
NSArray的用法
- 创建 objc @[@"Jack", @"Rose"] (返回是不可变数组)
- 访问 objc id d = array[1];
- 赋值 objc array[1] = @"jack";
NSDictionary的用法 +创建 objc @{ @"name" : @"Jack", @"phone" : @"10086" } (返回是不可变字典)
- 访问 objc id d = dict[@"name"];
- 赋值 objc dict[@"name"] = @"jack";

*:first-child {
margin-top: 0 !important; }
body > *:last-child {
margin-bottom: 0 !important; }

a {
color: #4183C4; }
a.absent {
color: #cc0000; }
a.anchor {
display: block;
padding-left: 30px;
margin-left: -30px;
cursor: pointer;
position: absolute;
top: 0;
left: 0;
bottom: 0; }

h1, h2, h3, h4, h5, h6 {
margin: 20px 0 10px;
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
cursor: text;
position: relative; }

h1 tt, h1 code {
font-size: inherit; }

h2 tt, h2 code {
font-size: inherit; }

h3 tt, h3 code {
font-size: inherit; }

h4 tt, h4 code {
font-size: inherit; }

h5 tt, h5 code {
font-size: inherit; }

h6 tt, h6 code {
font-size: inherit; }

h1 {
font-size: 28px;
color: black; }

h2 {
font-size: 24px;
border-bottom: 1px solid #cccccc;
color: black; }

h3 {
font-size: 18px; }

h4 {
font-size: 16px; }

h5 {
font-size: 14px; }

h6 {
color: #777777;
font-size: 14px; }

p, blockquote, ul, ol, dl, li, table, pre {
margin: 15px 0; }

a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0; }

h1 p, h2 p, h3 p, h4 p, h5 p, h6 p {
margin-top: 0; }

li p.first {
display: inline-block; }
li {
margin: 0; }
ul, ol {
padding-left: 30px; }

ul :first-child, ol :first-child {
margin-top: 0; }

blockquote {
border-left: 4px solid #dddddd;
padding: 0 15px;
color: #777777; }
blockquote > :first-child {
margin-top: 0; }
blockquote > :last-child {
margin-bottom: 0; }

img {
max-width: 100%; }

code, tt {
margin: 0 2px;
padding: 0 5px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px; }

pre code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent; }

.highlight pre {
background-color: #f8f8f8;
border: 1px solid #cccccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px; }

常见的结构体

本小节知识点:

【理解】NSPoint和CGPoint
【理解】NSSize和CGSize
【理解】NSRect和CGRect
【理解】常见的结构体使用注意

1.NSPoint和CGPoint

CGPoint和NSPoint是同义的

typedef CGPoint NSPoint;

CGPoint的定义

struct CGPoint {

  CGFloat x;

  CGFloat y;

};

typedef struct CGPoint CGPoint;

typedef double CGFloat;

CGPoint代表的是二维平面中的一个点
- 可以使用CGPointMake和NSMakePoint函数创建CGPoint

2.NSSize和CGSize

CGSize和NSSize是同义的

typedef CGSize NSSize;

CGSize的定义

struct CGSize {

  CGFloat width;

  CGFloat height;

};

typedef struct CGSize CGSize;

CGSize代表的是二维平面中的某个物体的尺寸(宽度和高度)
- 可以使用CGSizeMake和NSMakeSize函数创建CGSize

3.NSRect和CGRect

CGRect和NSRect是同义的

typedef CGRect NSRect;

CGRect的定义

struct CGRect {

  CGPoint origin;

  CGSize size;

};

typedef struct CGRect CGRect;

CGRect代表的是二维平面中的某个物体的位置和尺寸
- 可以使用CGRectMake和NSMakeRect函数创建CGRect

4.常见的结构体使用注意

苹果官方推荐使用CG开头的:
- CGPoint
- CGSize
- CGRect

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OC基础(24)

NSMutableArray基本概念

本小节知识点:

1.NSMutableArray介绍

2.NSMutableArray基本用法

3.NSMutableArray 错误用法

NSDictionary基本概念

本小节知识点:

1.NSDictionar基本概念

2.NSDictionary的创建

3.NSDictionary的遍历

4.NSDictionary文件操作

NSMutableDictionary基本概念

本小节知识点:

1.NSMutableDictionary 基本概念

2.NSMutableDictionary的常见操作

3.NSMutableDictionary的简写

4.NSDictionary和NSArray对比

常见的结构体

本小节知识点:

1.NSPoint和CGPoint

2.NSSize和CGSize

3.NSRect和CGRect

4.常见的结构体使用注意

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