在这里我要说一下，ios开发的知识点都偏于基础，我只记录了一些基础的知识点，并进行了扩展，适合入门的朋友：
【IOS初学者】UITableView与自定义UITableViewCell
【IOS初学者】bundle知识点总结
【IOS开发初学者】UINavigationController详解
NSArray
初始化
//1)创建一个空数组
NSArray *arr1 = [NSArray array];
//创建数组,只有一个元素
NSArray *arr2 = [NSArray arrayWithObject:@"aaa"];
//创建数组,有多个元素
// nil 表示数组赋值结束
NSArray *arr3 = [NSArray arrayWithObjects:@"aaa",@"bbb", nil];
//调用对象方法,创建数组
NSArray *arr4 = [[NSArray alloc] initWithObjects:@"aaa",@"bbb", nil];
//用一个数组可以创建另外一个数组
NSArray *arr5 = [NSArray arrayWithArray:arr3];
//使用@
NSArray *arr6 = @[@"aaa",@"bbb",@"ccc",@"ddd"];
常用方法
//获取数组的长度
NSLog(@"%ld",arr3.count);
//根据下标,获取下标对应的对象
NSLog(@"%@",[arr3 objectAtIndex:1]);
NSLog(@"%@",arr3[1]);
//返回元素的下标
NSUInteger loc = [arr3 indexOfObject:@"bbb"];
NSLog(@"%ld",loc);
//数组中是否包含了某个元素
if([arr3 containsObject:@"gggg"]){
NSLog(@"包含此元素");
}else{
NSLog(@"不包含");
}
NSLog(@"arr5 = %@",arr5);
对应log：
2017-02-24 09:35:12.836 TestArray[7023:601929] 2
2017-02-24 09:35:12.837 TestArray[7023:601929] bbb
2017-02-24 09:35:12.837 TestArray[7023:601929] bbb
2017-02-24 09:35:12.837 TestArray[7023:601929] 1
2017-02-24 09:35:12.837 TestArray[7023:601929] 不包含
2017-02-24 09:35:12.837 TestArray[7023:601929] arr5 = (
aaa,
bbb
)
遍历
//普通的方式,通过下标访问
for (int i=0; i<arr3.count; i++) {
NSLog(@"-> %@",arr3[i]);
}
// 快速枚举法 for循环的增强形式
for (NSString * str in arr3) {
NSLog(@"---> %@",str);
}
//使用block的方式,进行访问
[arr3 enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
if(idx == 2){
*stop = YES; //停止
}else{
NSLog(@"idx = %ld,obj = %@",idx,obj);
}
}];
打印log如下：
2017-02-24 09:46:33.215 TestArray[7047:609202] -> aaa
2017-02-24 09:46:33.215 TestArray[7047:609202] -> bbb
2017-02-24 09:46:33.215 TestArray[7047:609202] ---> aaa
2017-02-24 09:46:33.215 TestArray[7047:609202] ---> bbb
2017-02-24 09:46:33.215 TestArray[7047:609202] idx = 0,obj = aaa
2017-02-24 09:46:33.215 TestArray[7047:609202] idx = 1,obj = bbb
Program ended with exit code: 0
读写
- 写
NSArray *array = [NSArray arrayWithObjects:@"one",@"zbz",@"cgx",@"sb",@"cjk",@"senni", nil];
BOOL isWrite = [array writeToFile:@"/Users/xxxx/Desktop/arr.xml" atomically:YES];
- 读
NSArray *readArr = [NSArray arrayWithContentsOfFile:@"/Users/xxxx/Desktop/arr.xml"];
NSArray与字符串
- 数组拼接字符串
NSArray *arr6 = @[@"aaa",@"bbb",@"ccc",@"ddd"];
NSString *str = [arr6 componentsJoinedByString:@"-"];
NSLog(@"str = %@",str);
- 字符串拆分为数组
NSArray *arr7 = [str componentsSeparatedByString:@"-"];
NSLog(@"%@",[arr7 firstObject]);
NSLog(@"%@",[arr7 lastObject]);
NSLog(@"%@",arr7[1]);
看下打印log：
2017-02-24 09:58:04.852 TestArray[7107:619117] str = aaa-bbb-ccc-ddd
2017-02-24 09:58:04.852 TestArray[7107:619117] aaa
2017-02-24 09:58:04.853 TestArray[7107:619117] ddd
2017-02-24 09:58:04.853 TestArray[7107:619117] bbb
Program ended with exit code: 0
NSMutableArray
初始化
NSMutableArray *arr1 = [NSMutableArray array];
//创建的时候初始化一个元素
NSMutableArray *arr2 = [NSMutableArray arrayWithObject:@"aaa"];
//创建数组的时候,初始化多个元素
NSMutableArray *arr3 = [NSMutableArray arrayWithObjects:@"bbb",@"ccc",@"ddd",nil];
//创建一个数组,并且指定长度,
NSMutableArray *arr4 = [NSMutableArray arrayWithCapacity:5];
操作
- 添加
[arr1 addObject:@"ccc"];
[arr1 insertObject:@"ddd" atIndex:0];
- 删除
/删除指定元素
[arr1 removeObject:@"aaa"];
//根据角标删除元素
[arr1 removeObjectAtIndex:1];
//删除所有元素
[arr1 removeAllObjects];
- 修改
[arr3 replaceObjectAtIndex:1 withObject:@"aaa"];
arr3[1] = @"ccc";
- 查找
BOOL isSearch = [arr3 containsObject:@"ddd"];
NSLog(@"%d",isSearch);
- 交换
NSMutableArray *arr5 =[NSMutableArray arrayWithObjects:@1,@2,@3,@4,@5, nil];
[arr5 exchangeObjectAtIndex:0 withObjectAtIndex:4];
NSLog(@"%@",arr5);
遍历
NSMutableArray的遍历可以使用NSArray的方式进行遍历
NSDictionary
创建
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"lnj", @"name", @"12345678", @"phone", @"天朝", @"address", nil];
NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};
获取元素
[dict objectForKey:@"name”];
dict[@"name”];
遍历
NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};
for (NSString *key in dict) {
NSLog(@"key = %@, value = %@", key, dict[key]);
}
或
[dict enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) {
NSLog(@"key = %@, value = %@", key, obj);
}];
读写
- 读
NSDictionary *newDict = [NSDictionary dictionaryWithContentsOfFile:@"/Users/LNJ/Desktop/dict.plist"];
NSLog(@"newDict = %@", newDict);
- 写
NSDictionary *dict = @{@"name":@"lnj", @"phone":@"12345678", @"address":@"天朝"};
BOOL flag = [dict writeToFile:@"/Users/LNJ/Desktop/dict.plist" atomically:YES];
NSLog(@"flag = %i", flag);
NSMutableDictionary
初始化
NSMutableDictionary *dic2 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"v1",@"key1",@"v2",@"key2",nil];
NSMutableDictionary *dict1 = [NSMutableDictionary dictionary];
NSMutableDictionary *dict2 = [NSMutableDictionary dictionaryWithCapacity:3];
添加元素
[dic2 addEntriesFromDictionary:dic3];
[dic2 setValue:@"value3" forKey:@"key3"];
删除元素
//删除指定key
[dic1 removeObjectForKey@"key1"];
//删除指定key数组
NSArray *array = [NSArray arrayWithObjects:@"key1", nil];
[dic2 removeObjectsForKeys:array];
//移除字典所有对象
[dic1 removeAllObjects];
修改元素
[dict1 setObject:@"zhaosi" forKey:@"ls"];
//简写形式
dict1[@"ls"] = @"xxxxx";
NSLog(@"%@",dict1);
遍历
NSMutableDictionary *dictionary3 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"value",@"key",@"value2",@"key2",@"value3",@"key3",@"value4",@"key4",@"value5",@"key5",@"value6",@"key6", nil];
for (id key in dictionary3) {
id obj = [dictionary3 objectForKey:key];
NSLog(@"快速枚举--->obj= %@",obj);
}
//一般枚举
NSArray *keys = [dictionary3 allKeys];
float length = [keys count];
for (int i = 0; i < length; i ++) {
id key = [keys objectAtIndex:i];
id obj = [dictionary3 objectForKey:key];
NSLog(@"一般枚举--->%@",obj);
}
//通过枚举类枚举
NSEnumerator *enumerator3 = [dictionary3 keyEnumerator];
id key = [enumerator3 nextObject];
while (key) {
id obj = [dictionary3 objectForKey:key];
NSLog(@"通过枚举类枚举--->%@",obj);
key = [enumerator3 nextObject];
}
