Foundation框架內容

1 數字對象

1.      NSNumber:數字對象創建如下：

NSNumber *num, intNum, floatNum;
NSInteger myInt;
 
//integer
intNum = [NSNumber numberWithInteger:10];
myInt = [intNum integerValue];
NSLog("%li",(long)myInt );
 
//float
floatNum = [NSNumber numberWithFloat:10.11];
NSLog("%g",[floatNum floatValue]);
 
//char
num = [NSNumber numberWithChar:'a'];
NSLog("%c",[num charValue]);
 
//double
num = [NSNumber numberWithDouble:1234e+15];
NSLog("%lg",[num doubleValue]);
 
//判斷數字是否相等
if( [num isEqualToNumber:floatNum]==YES ){}
 
//判斷數字大小
if( [num compare:floatNum]==NSOrderedAscending )  //順序

NSInteger和NSUInteger不是NS對象，而是typedef。NSInteger是64位long或32位int。

 

2.      初始化方式

 

2 字符串對象

NSString *str = @”hello world”;  
NSLog("%@",str);

NSString 使用@符號表示，並使用”%@”格式化輸出，還可以格式化輸出其他對象。

 

3 description方法

         “%@”格式化其實是調用的NSObject的description方法，如果沒有覆寫description方法，只能打印對象的類名和內存地址，NSString已經覆寫了description方法。

 

4 不可變字符串

<span style="font-weight: normal;">NSString *str1 = @"hello world A";
NSString *str2 = @"hello world B";
NSString *res;
NSRange *range;
 
//字符串的長度
NSLog("%lu",[str1 length]);
 
//字符串複製到另一個
res = [NSString stringWithString:str1];
NSLog("%@",res);
 
//添加字符串到末尾
str2 = [str1 stringByAppendingString:str2];
 
//判斷是否相等
if([str1 isEqualToString:str2]==YES)
 
//轉換爲大寫
res = [str1 uppercaseString];
NSLog("%@", [res UTF8String]);NSString *str1 = @"hello world A";
NSString *str2 = @"hello world B";
NSString *res;
 
//字符串的長度
NSLog("%lu",[str1 length]);
 
//字符串複製到另一個
res = [NSString stringWithString:str1];
NSLog("%@",res);
 
//添加字符串到末尾
str2 = [str1 stringByAppendingString:str2];
 
//判斷是否相等
if([str1 isEqualToString:str2]==YES)
 
//轉換爲大寫
res = [str1 uppercaseString];
NSLog("%@", [res UTF8String]);
 
 
//從字符串提取
res = [str1 substringToIndex:3];
 
//從index往後截取
res = [str1 substringFromIndex:5];
 
//截取8到13
res = [str1 substringWithRange:NSMakeRange(8,6)];
 
//查找字符串 獲取NSRange對象
range = [str1 rangeOfString:@"hello"]</span>

5 可變字符串

NSMutableString是可變的字符串，繼承自NSString。

NSMutableString *mstr;
//創建可變字符串
mstr = [NSMutableString stringWithString:@"hello"];
 
//插入字符串
[mstr insertString:@"world" atIndex:[mstr length];
 
//末尾拼接
[mstr appendString:"world"];
 
//根據範圍刪除字符串
[mstr deleteCharactersInRange:NSMakeRange(3,3)];
 
//設置字符串
[mstr setString:@"hello world"];
 
//替換字符串
[mstr replaceCharactersInRange:NSMakeRange(1,1) withString:@"1"];

6 數組NSArray

NSArray *week = [NSArray arrayWithObjects:@"mon",@"tue",@"wed",@"thu",@"fri",@"sat",@"sun"];
for(int i=0; i<7; i++){
    NSLog("%@",[week objectAtIndex:i]);
}

7 可變數組

NSMutableArray *nums = [NSMutalbeArray array];
NSNumber *number;
 
for(int i=0; i<10; i++){
    number = [nums addObject:[NSNumber numberWithInteger:i]];
}

8 詞典對象dictionary

詞典對象類似Java的Map，如下：

NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];
[dictionary setObject:@"字母A" forKey:@"a"];
[dictionary setObject:@"字母B" forKey:@"b"];
 
NSLog("%@",[dictionary objectForKey:@"a"]);
 
NSMutableDictionary *dictionary = [NSMutableDictionary dictionaryWithObjectAndKeys:
    @"字母A",@"A",@"字母B",@"B"];
for(NSString *key in dictionary){
    NSLog("%@",[dictionary objectForKey:key]);
}

 

9 SET對象

#define INTOBJ(v) [NSNumber numberWithInteger:v];
NSMutalbeSet *set1 = [NSMutableSet setWithObjects:INTOBJ(1),INTOBJ(2),INTOBJ(3),nil];
NSMutalbeSet *set2 = [NSMutableSet setWithObjects:INTOBJ(4),INTOBJ(5),INTOBJ(6),nil];
 
//是否相等
if( [set1 isEqualToSet:set2]==YES )
//是否包含
if( [set1 containsObject:INTOBJ(10)]==YES )
//添加和刪除
[set1 addObject:INTOBJ(20)];
[set1 removeObject:INTOBJ(1)];
//獲取交集
[set1 intersectSet:set2]
//合併
[set1 unionSet:set2];