OC Foundation框架—字符串操作方法及习题

 #import <Foundation/Foundation.h>

 int main(int argc, const char * argv[]) {
     @autoreleasepool {
         /*
          不可变字符串
          1.创建字符串
             实例方法（3种）
             类方法（3种）
          2.不可变字符串：
            统计长度（2种）
            索引提取 (3种)
            比较 (3种)
            查照字符串位置（1种）
            判断前后缀
            转换数字
            大小写转换
            字符串提取

          可变字符串
          1.创建可变字符串
          2.可变字符串的操作
          增（3种）删（1种）改（1种）查

          */

         //实例方法（3种）
         NSString *str1 = @"";
         NSString *str2 = [[NSString alloc] initWithFormat:@"%d4567",];
 //        NSString *str3 = [[NSString alloc] initWithString:str2];//传的是对象

         //类方法（3种）
         NSString *str4 = [NSString stringWithFormat:@"Abc%@eFg",@"d"];
 //        NSString *str5 = [NSString stringWithString:str4];

         //统计长度（2种）
         NSUInteger length = [str1 length];
         NSUInteger length1 = str1.length;
         NSLog(@"%lu %lu",length,length1);

         //索引提取 (3种)
         NSString *newStr1 = [str1 substringFromIndex:];
         NSLog(@"%@",newStr1);
         NSString *newStr2 = [str1 substringToIndex:];
         NSLog(@"%@",newStr2);
         NSString *newStr3 = [str1 substringWithRange:NSMakeRange(, )];
         NSLog(@"%@",newStr3);

         //比较 (3种)
         if ([str1 isEqualToString:str2]) {
             NSLog(@"相同");
         }else
             NSLog(@"不相同");

         if ([str1 compare:str2] == NSOrderedAscending) {
             NSLog(@"str1>str2");
         }
         else if ([str1 compare:str2] == NSOrderedDescending)
             NSLog(@"str1<str2");
         else if ([str1 compare:str2] == NSOrderedSame)
             NSLog(@"==");

         if ([str1 caseInsensitiveCompare:str2] == NSOrderedAscending) {
             NSLog(@"str1>str2");
         }
         else if ([str1 caseInsensitiveCompare:str2] == NSOrderedDescending)
             NSLog(@"str1<str2");
         else if ([str1 caseInsensitiveCompare:str2] ==NSOrderedSame)
             NSLog(@"==");

         // 查找字符串位置
         NSRange range = [str1 rangeOfString:str2];
         if (range.location != NSNotFound) {
             NSLog(@"location:%lu  length:%lu",range.location,range.length);

         } else {
             NSLog(@"没找到");
         }

         //判断前后缀（2种）
         BOOL flag = [str4 hasPrefix:@"abc"];
         NSLog(@"%d",flag);

         BOOL anotherFlag = [str4 hasSuffix:@"fg"];
         NSLog(@"%d",anotherFlag);

         //转换数字（4种）
         int number = [str1 intValue];
         NSLog(@"%d",number);

         NSInteger number1 = [str1 intValue];
         NSLog(@"%ld",number1);

         NSString *str6 = @"1234567.89";
         double number2 = [str6 doubleValue];
         NSLog(@"%lf",number2);

         //大小写转换
         NSString *upStr = [str4 uppercaseString];
         NSLog(@"%@",upStr);
         NSString *lowStr = [str4 lowercaseString];
         NSLog(@"%@",lowStr);
         NSString *tempStr = [str4 capitalizedString];
         NSLog(@"%@",tempStr);

         // 可变字符串
         // 实例方法
         NSMutableString *muStr1 = [[NSMutableString alloc]
                                    initWithFormat:@"1%d3",];

         NSMutableString *muStr2 = [[NSMutableString alloc]
                                    initWithString:@""];

         NSMutableString *muStr3 = [[NSMutableString alloc]
                                    initWithCapacity:];

         // 类方法
         NSMutableString *muStr4 = [NSMutableString stringWithFormat:@"4%d6",];

         NSMutableString *muStr5 = [NSMutableString stringWithString:@""];

         NSMutableString *muStr6 = [NSMutableString stringWithCapacity:];

         //增（3种）

         [muStr1 appendFormat:@"%d",];
         NSLog(@"%@",muStr1);

         [muStr2 appendString:@""];
         NSLog(@"%@",muStr2);

         [muStr3 insertString:@"abcdefghijklmn" atIndex:];
         NSLog(@"%@",muStr3);

         [muStr4 insertString:@"abcdefghijklmn" atIndex:];
         NSLog(@"%@",muStr4);

         //删除
         [muStr5 deleteCharactersInRange:NSMakeRange(, )];
         NSLog(@"%@",muStr5);

         //改
         [muStr6 replaceCharactersInRange:NSMakeRange(, ) withString:@""];
         NSLog(@"%@",muStr6);

         [muStr5 replaceCharactersInRange:NSMakeRange(, ) withString:@"abcd"];
         NSLog(@"%@",muStr5);

 #import <Foundation/Foundation.h>

 @interface MyStringTools : NSObject

 /*

  1.创建一个类，要求：
  (1)、定义一个方法，能完成字符串逆序输出的操作
  (2)、定义一个方法，能删除某字符串中的指定字串

     myStringTool  delete:(NSString*) InString:(NSString*)

  (3)、定义一个方法，能查找某字符串在某字符串中出现的次数
  (4)、定义一个方法，能传入两个字符串,将这个字符串组合成一个新的对称字符串返回
  (5)、定义一个方法，能将原字符串进行小写转大写，大写转小写
  (6)、定义一个方法，能压缩传入的字符串
  （比如输入@"aaabbbcceaa" 输出@"3a3b2c1e2a"）
  (7)、定义一个方法，能对传入的字符串按照字母顺序进行排列
  （比如输入@"aczabczab"  输出@"aaabbcczz”）
  (8)、定义一个方法，能够替换某字符串中的某个指定字串
  (9)、定义一个方法，能够获取指定字符串长度。
  */

 //定义一个方法，能完成字符串逆序输出的操作
 +(NSString *) reverseOrder:(NSString *) str1;

 //定义一个方法，能删除某字符串中的指定字串
 +(NSString *) deleteTheString:(NSString *) str1
                      inString:(NSString *) str2;

 //定义一个方法，能查找某字符串在某字符串中出现的次数
 +(NSInteger) findNumberOfString:(NSString *) str1
                        inString:(NSString *) str2;

 //定义一个方法，能传入两个字符串,将这个字符串组合成一个新的对称字符串返回
 +(NSString *) makeUpString:(NSString *) str1
                  andString:(NSString *) str2;

 //定义一个方法，能将原字符串进行小写转大写，大写转小写
 +(NSString *) convertLetters:(NSString *) str1 andCase:(NSString *) mycase;

 //定义一个方法，能压缩传入的字符串
 +(NSString *) compressString:(NSString *) str1;

 //定义一个方法，能对传入的字符串按照字母顺序进行排列
 +(NSString *) theStringOrder:(NSString *) str1;

 //定义一个方法，能够替换某字符串中的某个指定字串
 +(NSString *) replaceTheString:(NSString *) str1
                     fromString:(NSString *) str2
                       toString:(NSString *) str3;

 //定义一个方法，能够获取指定字符串长度
 +(NSInteger) obtainTheLength:(NSString *) str1;
 @end

 #import "MyStringTools.h"

 @implementation MyStringTools

 +(NSString *) reverseOrder:(NSString *) str1
 {
     NSMutableString *string = [NSMutableString stringWithString:str1];
     NSMutableString *mutableString =[NSMutableString stringWithString:str1];

     for (int i=; i<string.length; i++) {
         //方法1
         NSString *subStr1 = [string substringWithRange:NSMakeRange(i, )];
         NSString *subStr2 = [string substringWithRange:
                              NSMakeRange(string.length - i-, )];
         // 取长度和范围
         NSRange range1 = [string rangeOfString:subStr1];
         NSRange range2 = [string rangeOfString:subStr2];

         [mutableString replaceCharactersInRange:range1 withString:subStr2];
         [mutableString replaceCharactersInRange:range2
                                      withString:subStr1];
     }
         return mutableString;

         //方法2
 //        NSString *tempStr = [string substringFromIndex:string.length-1];
 //
 //        [string insertString:tempStr atIndex:i];
 //
 //        [string deleteCharactersInRange:NSMakeRange(string.length-1,1)];
 //         }
 //    return string

 }

 +(NSString *) deleteTheString:(NSString *) str1
                      inString:(NSString *) str2
 {
     NSMutableString *string = [NSMutableString stringWithString:str2];

     NSRange range = [string rangeOfString:str1];

     if (range.location !=NSNotFound) {
         [string deleteCharactersInRange:range];
     }
     else
         NSLog(@"没有发现字符");
     return string;
 }

 +(NSInteger) findNumberOfString:(NSString *) str1
                        inString:(NSString *) str2
 {
     int i,count=;

     NSMutableString *string = [NSMutableString stringWithString:str2];

     for (i=; i<string.length; i++) {

         NSRange range = [string rangeOfString:str1];

         if (range.location !=NSNotFound) {
         [string deleteCharactersInRange:range];
             count++;
         }
     }
     return count;
 }

 +(NSString *) makeUpString:(NSString *) str1
                  andString:(NSString *) str2
 {
     NSMutableString *string = [NSMutableString stringWithString:str2];
     [string appendString:str1];

     for (NSInteger i=string.length-; i>=; i--) {
         [string appendString:[string substringWithRange:NSMakeRange(i, )]];

     }
     return string;
 }

 +(NSString *) convertLetters:(NSString *) str1 andCase:(NSString *) mycase
 {
     NSMutableString *string = [NSMutableString stringWithString:str1];

     if ([mycase isEqualToString:@"大写"]) {
         return [string uppercaseString];
     }
     else
         return [string lowercaseString];
 }

 +(NSString *) compressString:(NSString *) str1
 {
     int i;
     NSMutableString *string = [NSMutableString stringWithString:str1];
     NSMutableString *newString;
     NSMutableString *newString1 = [NSMutableString stringWithString:@""];

     for (i=; i<string.length; i++) {

         NSString *tempStr = [string substringWithRange:NSMakeRange(, )];
         int count=;

         for (int j=; j<string.length; j++) {

             NSString *tempStr1 = [string substringWithRange:NSMakeRange(, )];

         if ([tempStr1 isEqualToString:tempStr]) {

             [string deleteCharactersInRange:NSMakeRange(, )];
             count++;
         }
         }
         newString = [NSMutableString stringWithFormat:@"%d%@",count,tempStr];
         [newString1 appendString:newString];

     }
     return newString1;

 }

 +(NSString *) theStringOrder:(NSString *) str1
 {
     NSMutableString *string = [NSMutableString stringWithString:str1];

     for (int i=; i<string.length-; i++) {
         for (int j=; j<string.length-; j++) {

             NSString *tempStr1=[string substringWithRange:NSMakeRange(j, )];
             NSString *tempStr2=[string substringWithRange:NSMakeRange(j+, )];

             NSRange range1 = [string rangeOfString:tempStr1];
             NSRange range2 = [string rangeOfString:tempStr2];

             if ([tempStr1 compare:tempStr2]==NSOrderedAscending) {

                 [string replaceCharactersInRange:range2 withString:tempStr1];
                 [string replaceCharactersInRange:range1 withString:tempStr2];
             }
             }
         }
     return string;
 }

 +(NSString *) replaceTheString:(NSString *) str1
                     fromString:(NSString *) str2
                       toString:(NSString *) str3
 {
     NSMutableString *string = [NSMutableString stringWithString:str2];

     NSRange range = [string rangeOfString:str1];
     [string replaceCharactersInRange:range withString:str3];
     return string;
 }

 +(NSInteger) obtainTheLength:(NSString *) str1
 {
     return str1.length;
 }

 @end

 #import <Foundation/Foundation.h>
 #import "MyStringTools.h"

 int main(int argc, const char * argv[]) {
     @autoreleasepool {

         NSString *mystring=[NSString stringWithFormat:@"abcdef"];

         NSLog(@"%@",[MyStringTools reverseOrder:mystring]);

         NSLog(@"%@",[MyStringTools deleteTheString:@"bc"
                                           inString:mystring]);

         NSLog(@"%ld",[MyStringTools findNumberOfString:@"bc"
                                               inString:@"abcdfebcbbc"]);

         NSLog(@"%@",[MyStringTools makeUpString:@"abcdef"
                                       andString:@"gh"]);

         NSLog(@"%@",[MyStringTools convertLetters:@"aBcDeF"
                                           andCase:@"大写"]);

         NSLog(@"%@",[MyStringTools compressString:@"hhfffkkkkkiinil"]);

         NSLog(@"%@",[MyStringTools theStringOrder:@"sadcbfw"]);

         NSLog(@"%@",[MyStringTools replaceTheString:@"sdf"
                                          fromString:@"asdfghjkl"
                                            toString:@"abc"]);

         NSLog(@"%lu",[MyStringTools obtainTheLength:@"qwert"]);

     }
     return ;
 }