NSString NSMutableString objective-c中字符串操作

来源：互联网发布：淘宝联盟怎么分享不了编辑：程序博客网时间：2024/04/29 15:11
 // 1.NSString 不可变字符串        // 使用字面量创建字符串对象        NSString *str1 = @"字符串1";        // 使用初始化方法创建        NSString *str2 = [[NSString alloc] initWithFormat:@"age = 18"]; // 不用占位符        NSLog(@"%@",str2);        NSInteger a = 10, b = 20;        NSString *res = [[NSString alloc] initWithFormat:@"%ld", a + b]; // 用占位符        NSLog(@"res = %@", res);        // 使用便利构造器创建字符串对象        NSString *str4 = [NSString stringWithFormat:@"字符串4"];   // 对应初始化方法        NSLog(@"%@", str4);        // 获取字符串长度        NSUInteger l = [str4 length];  // 给字符串对象发送length消息，可以获取到字符串长度        NSLog(@"length = %ld", l);        // 判断后缀   区分大小写        NSString *str5 = @"icon.png";        BOOL b1 = [str5 hasPrefix:@"ic"]; //  没有分割，写多少字符都可以        NSLog(@"%d", b1);        // 比较字符串相同        BOOL b2 = [str5 isEqualTo:@"icon.png"];        NSLog(@"%d", b2);        // 截取字符串 NSRange        NSString *str6 = [str5 substringWithRange:NSMakeRange(4, 4)];        NSLog(@"%@", str6);        //  拼接字符串        NSString *name = @"小泽";        NSString *newStr = [name stringByAppendingString:@"老师"];        NSLog(@"%@", newStr);        //  替换字符串        NSString *str8_1 = [newStr stringByReplacingOccurrencesOfString:@"老师" withString:@"菇凉"];        NSLog(@"str8_1 = %@", str8_1);        NSString *str8_2 = [newStr stringByReplacingCharactersInRange:NSMakeRange(2, 2) withString:@"菇凉你好"];        NSLog(@"str8_2 = %@", str8_2);        //  比较字符串        NSString *str9 = @"abc";        NSString *str10 = @"abcd";        NSComparisonResult res1 = [str9 compare:str10];        NSLog(@"res1 = %ld", res1);        //  字符串和数值类型的转换        NSString *str11 = @"123.4";        NSLog(@"%.2f", [str11 doubleValue]);        //  大小写转换        NSString *str7 = @"Zhao YA dong";        NSLog(@"%@", [str7 lowercaseString]);        NSLog(@"%@", [str7 uppercaseString]);        NSLog(@"%@", [str7 capitalizedString]);        // 可变字符串        NSMutableString *mutableStr1 = [[NSMutableString alloc] initWithFormat:@"abc"];        NSLog(@"%@", mutableStr1);        // 拼接        [mutableStr1 appendFormat:@"def"];        [mutableStr1 appendString:@"gh"];        NSLog(@"%@", mutableStr1);        // 删除        [mutableStr1 deleteCharactersInRange:NSMakeRange(2, 1)];        NSLog(@"%@", mutableStr1);        // 插入        [mutableStr1 insertString:@"cc" atIndex:2];        NSLog(@"%@", mutableStr1);        // 修改        [mutableStr1 replaceCharactersInRange:NSMakeRange(0, 2) withString:@"yadong"];        NSLog(@"%@", mutableStr1);
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