1 #import <Foundation/Foundation.h> 2 3 int main(int argc, const char * argv[]) 4 { 5 @autoreleasepool 6 { 7 #pragma mark - NSString 8 char *s = "Hello Objective-C";//C语言的字符串格式 9 NSString *str = @"Hello"; 10 //OC、C字符串的转换：C-->OC 11 NSString *str1 = [NSString stringWithUTF8String:s];//UTF8是一种编码格式 12 NSLog(@"str1 = %@", str1); 13 //OC-->C 14 NSLog(@"str2 = %s", [str UTF8String]); 15 16 //创建字符串 17 NSString *str3 = @"IOS"; 18 NSString *str4 = [[NSString alloc] init]; 19 str4 = @"IOS"; 20 // 格式化字符串 21 int a = 10; 22 int b = 20; 23 NSString *str5 = [NSString stringWithFormat:@"a = %d b = %d", a, b]; 24 NSLog(@"str5 = %@", str5); 25 //拼接字符串 26 NSString *str6 = [[str5 stringByAppendingString:@" and "] stringByAppendingString:str3]; 27 NSLog(@"str6 = %@", str6); 28 //大小写转换 29 //转换小写 30 NSString *str7 = @"aBcdEFG"; 31 NSString *str8 = [str7 lowercaseString]; 32 NSLog(@"str8 = %@", str8); 33 //转换大写 34 NSString *str9 = [str7 uppercaseString]; 35 NSLog(@"str9 = %@", str9); 36 37 //前缀和后缀的判断 38 NSString *str10 = @"www.songlei.com"; 39 //判断前缀 40 BOOL hasPrefix = [str10 hasPrefix:@"www."]; 41 if (hasPrefix) 42 { 43 NSLog(@"有对应前缀"); 44 } 45 else 46 { 47 NSLog(@"没有对应前缀"); 48 } 49 //判断后缀 50 BOOL hasSuffix = [str10 hasSuffix:@".com"]; 51 if (hasSuffix) 52 { 53 NSLog(@"有对应后缀"); 54 } 55 else 56 { 57 NSLog(@"没有对应后缀"); 58 } 59 60 //判断两个字符串是否相同 61 NSString *str11 = @"Hello"; 62 NSString *str12 = @"Hello "; 63 if ([str11 isEqualToString:str12]) 64 { 65 NSLog(@"两个字符串一致"); 66 } 67 else 68 { 69 NSLog(@"两个字符串不一致"); 70 } 71 72 //***比较字符串*** 73 // NSComparisonResult 74 75 //分割//按照指定字符分割字符串 76 NSString *str13 = @"a, b, c, d, e, f"; 77 NSArray *strArray = [str13 componentsSeparatedByString:@", "]; 78 for (NSString *str in strArray) 79 { 80 NSLog(@"str = %@", str); 81 } 82 //按照指定范围分割字符串 83 NSRange range = NSMakeRange(3, 9); 84 NSString *str14 = [str13 substringWithRange:range]; 85 NSLog(@"str14 = %@", str14); 86 //从某一位开始截取后面的字符串 87 NSString *str15 = [str13 substringFromIndex:9]; 88 NSLog(@"str15 = %@", str15); 89 //从开头截取到某一位 90 NSString *str16 = [str13 substringToIndex:9]; 91 NSLog(@"str16 = %@", str16); 92 //将字符串拆分为每一个字符 93 int j = (int)[str13 length]; 94 for(int i = 0; i < j; ++i) 95 { 96 NSLog(@"%c", [str13 characterAtIndex:i]); 97 } 98 99 //查找 100 NSString *str17 = @"ab cd ef gh ij ab"; 101 //查找指定字符串的位置 102 NSRange range1 = [str17 rangeOfString:@"ab"];//(这个查找是一个正向查找) 103 NSLog(@"range1.location:%ld range1.length:%ld", range1.location, range1.length); 104 105 //替换 106 NSString *str18 = @"Hello huashan, Hello songlei"; 107 //替换某一个范围的内容 108 NSString *str19 = [str18 stringByReplacingCharactersInRange:NSMakeRange(0, 5) withString:@"你好"]; 109 NSLog(@"str19 = %@", str19); 110 //用指定字符串替换字符串中的子串 111 /* 112 stringByReplacingOccurrencesOfString - 源字符串中要被替换的内容 withString - 替换字符串 113 */ 114 NSString *str20 = [str18 stringByReplacingOccurrencesOfString:@"Hello" withString:@"Hi"]; 115 NSLog(@"str20 = %@", str20); 116 117 #pragma mark - NSURL(路径类) 118 // 读取文件 119 //文件来源：1.本地文件。2.网络文件 120 //路径类 121 NSString *str21 = @"www.baidu.com"; 122 //网络路径 123 NSURL *httpURL = [NSURL URLWithString:str21]; 124 //本地路径 125 NSURL *fileURL = [NSURL fileURLWithPath:str21]; 126 //读取网络文件 127 NSString *httpStr = [NSString stringWithContentsOfURL:httpURL encoding:NSUTF8StringEncoding error:nil]; 128 NSLog(@"httpURL = %@", httpStr); 129 //读取本地文件 130 NSString *fileStr = [NSString stringWithContentsOfFile:@"/Users/hskj/Desktop/Test.txt" encoding:NSUTF8StringEncoding error:nil]; //Test.txt自己创建的纯文本文件，放在了桌面上 131 NSLog(@"fileStr = %@", fileStr); //fileStr = Hello IOS Songlei 132 133 //写入文件 134 NSString *str22 = @"Hello TravelColor"; 135 BOOL isOk = [str22 writeToFile:@"/Users/hskj/Desktop/Demo.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil]; 136 if (isOk) 137 { 138 NSLog(@"文件写入成功"); 139 } 140 else 141 { 142 NSLog(@"文件写入失败"); 143 } 144 145 } 146 return 0; 147 }
1 2016-08-10 14:42:32.165 FoundationFrame[1117:177889] str1 = Hello Objective-C 2 2016-08-10 14:42:32.166 FoundationFrame[1117:177889] str2 = Hello 3 2016-08-10 14:42:32.166 FoundationFrame[1117:177889] str5 = a = 10 b = 20 4 2016-08-10 14:42:32.166 FoundationFrame[1117:177889] str6 = a = 10 b = 20 and IOS 5 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] str8 = abcdefg 6 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] str9 = ABCDEFG 7 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] 有对应前缀 8 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] 有对应后缀 9 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] 两个字符串不一致 10 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] str = a 11 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] str = b 12 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] str = c 13 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] str = d 14 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] str = e 15 2016-08-10 14:42:32.167 FoundationFrame[1117:177889] str = f 16 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] str14 = b, c, d, 17 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] str15 = d, e, f 18 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] str16 = a, b, c, 19 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] a 20 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] , 21 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] 22 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] b 23 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] , 24 2016-08-10 14:42:32.168 FoundationFrame[1117:177889] 25 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] c 26 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] , 27 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] 28 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] d 29 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] , 30 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] 31 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] e 32 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] , 33 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] 34 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] f 35 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] range1.location:0 range1.length:2 36 2016-08-10 14:42:32.169 FoundationFrame[1117:177889] str19 = 你好 huashan, Hello songlei 37 2016-08-10 14:42:32.170 FoundationFrame[1117:177889] str20 = Hi huashan, Hi songlei 38 2016-08-10 14:42:32.186 FoundationFrame[1117:177889] httpURL = (null) 39 2016-08-10 14:42:32.186 FoundationFrame[1117:177889] fileStr = Hello IOS Songlei 40 2016-08-10 14:42:32.245 FoundationFrame[1117:177889] 文件写入成功 41 Program ended with exit code: 0