OC 字符串操作整理

  1 //
  2 //  main.m
  3 //  StringMK
  4 //
  5 //  Created by LXC on 16/1/7.
  6 //  Copyright © 2016年 LXC. All rights reserved.
  7 //  2016年01月07日23:51:29
  8 //
  9 
 10 #import <Foundation/Foundation.h>
 11 
 12 int main(int argc, const char * argv[]) {
 13     @autoreleasepool {
 14         // insert code here...
 15         NSLog(@"Hello, World!");
 16         
 17         //C
 18         char *s = "Hello C";
 19         //OC
 20         NSString *str = @"Hello";
 21         //C --> OC
 22         NSString *str1 = [NSString stringWithUTF8String:s];
 23         NSLog(@"str1 = %@",str1);
 24         //OC --> C
 25         NSLog(@"str2 = %s",[str UTF8String]);
 26         
 27         //创建字符串
 28         NSString *str3 = @"IOS";//不需要自己释放内存
 29         NSString *str4 = [[NSString alloc] init];//先分配内存 在初始化
 30         str4 = @"IOS";
 31         
 32         //格式化字符串
 33         int a = 10;
 34         int b = 20;
 35         
 36         NSString *str5 = [NSString stringWithFormat:@"a = %d,b = %d",a,b];
 37         NSLog(@"str5 = %@",str5);
 38         
 39         //拼接字符串
 40         NSString *str6 = [str5 stringByAppendingString:str3];
 41         NSLog(@"str6 = %@",str6);
 42         
 43         //大小写转换
 44         NSString *str7 = @"ASDASDA";
 45         NSString *str8 =  [str7 lowercaseString];
 46         NSLog(@"str8 = %@",str8);
 47         NSString *str9 = [str7 uppercaseString];
 48         NSLog(@"str9 = %@",str9);
 49         
 50         //前缀和后缀的判断
 51         NSString *str10 = @"www.liuxincheng.win";
 52         BOOL hasPrFix  = [str10 hasPrefix:@"www."];
 53         if (hasPrFix) {
 54             NSLog(@"YES");
 55         }else{
 56             NSLog(@"NO");
 57         }
 58         BOOL hasSuffix  = [str10 hasSuffix:@".win"];
 59         if (hasSuffix) {
 60             NSLog(@"YES");
 61         }else{
 62             NSLog(@"NO");
 63         }
 64 
 65         //判断两个字符川是否相同
 66         
 67         NSString *str11 = @"LXC";
 68         NSString *str12 = @" LXC";
 69         if ([str11 isEqualToString:str12]) {
 70             NSLog(@"SAME");
 71         }else{
 72             NSLog(@"diff");
 73         }
 74         
 75         //比较字符串 NSComparisonResult
 76         
 77         //分割字符串
 78         //按照指定字符分割字符串
 79         NSString *str13 = @"a,b,c,d,e,f";
 80         NSArray *strarray = [str13 componentsSeparatedByString:@","];
 81         for (NSString *str in strarray) {
 82             NSLog(@"STR = %@",str);
 83         }
 84         
 85         //按照范围切割字符串
 86         NSRange range = NSMakeRange(1,5);
 87         NSString *str14 = [str13 substringWithRange:range];
 88         NSLog(@"STR14 = %@",str14);
 89         
 90         //从某一位开始截取
 91         NSString *str15 = [str13 substringFromIndex:2];
 92         NSLog(@"STR15 = %@",str15);
 93         //截取到某一位
 94         NSString *str16 = [str13 substringToIndex:2];
 95         NSLog(@"STR16 = %@",str16);
 96         //拆分到每一个字符
 97         for(int i=0;i<[str13 length];i++){
 98             NSLog(@"STRCHAR =  %c",[str13 characterAtIndex:i]);
 99         }
100         
101         
102         //查找
103         NSString *str17 = @"ad ad fe ef cv gh";
104         NSRange range1 = [str17 rangeOfString:@"cv"];
105         NSLog(@"range.location : %ld range1.length : %ld",range1.location,range1.length);
106         
107         //替换
108         NSString *str18 = @"Hello ios ,hello lxc";
109         //替换某一个范围的内容
110         NSString *str19 = [str18 stringByReplacingCharactersInRange:NSMakeRange(0, 5) withString:@"LXC"];
111         NSLog(@"%@",str19);
112         
113         //用指定字符串替换原字符串中的字串
114         /*
115          第一个参数是被替换的内容
116          第二个参数是要替换的内容
117          */
118         NSString *str20 = [str18 stringByReplacingOccurrencesOfString:@"Hello" withString:@"ni hao"];
119         NSLog(@"%@",str20);
120         
121         //读取文件 文件来源
122         //本地文件 网络文件
123         
124         NSString *str21 = @"www.liuxincheng.win";
125         //网络路径
126         NSURL *httpURL = [NSURL URLWithString:str21];
127         //本地路径
128         NSString *str22 = @"/Users/lxc/Desktop/test.txt";
129         NSURL *fileURL = [NSURL fileURLWithPath:str22];
130         //读取网络文件
131         NSString *httpstr = [NSString stringWithContentsOfURL:httpURL encoding:NSUTF8StringEncoding error:nil];
132         //读取本地文件
133         NSString *filestr = [NSString stringWithContentsOfFile:str22 encoding:NSUTF8StringEncoding error:nil];
134         
135         NSLog(@"HTTP %@ FILE %@",httpstr,filestr);
136         
137         //写入文件
138         NSString *str23 = @"jinzhuanch";
139         BOOL isok =  [str23 writeToFile:@"/Users/lxc/Desktop/demo.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil];
140         
141         if (isok) {
142             NSLog(@"OK");
143         }else{
144             NSLog(@"NO");
145         }
146         //可变字符串是字符串的子类
147         NSMutableString *str24 = [[NSMutableString alloc] initWithCapacity:10];
148         [str24 setString:@"kun"];
149         
150         //追加字符串
151         [str24 appendFormat:@" siwole"];
152         NSLog(@"str24 = %@",str24);
153         int c = 10;
154         [str24 appendFormat:@" ---%i",c];
155         NSLog(@"str25 ---- %@",str24);
156         
157         //替换字符串
158         NSRange ranges = [str24 rangeOfString:@"siwole"];
159         [str24 replaceCharactersInRange:ranges withString:@"sleep"];
160         NSLog(@"str26 --- %@",str24);
161         
162         //插入字符串
163         [str24 insertString:@"OMG" atIndex:2];
164         NSLog(@"str27 == %@",str24);
165         
166         //删除字符串
167         NSRange rangess = [str24 rangeOfString:@"OMG"];
168         [str24 deleteCharactersInRange:rangess];
169         NSLog(@"str28 ==== %@",str24);
170     }
171     return 0;
172 }