Objective-c学习二 字符串的使用

#import<Foundation/Foundation.h>
int main(int argc,const char* argv[])
{
   
   /***********************字符串创建******************/
   NSString *str1 = @"直接给字符串赋值"; //字符串赋值
   NSLog(@"%@",str1);

   //字符串格式化各种数据类型
   NSString *str2 = [NSString stringWithFormat:@"名字：%@ 年龄%d 邮箱:%s 钱: %d 籍贯:%d",@"哦哦哦",13,"g@t.com",14,4]; //不能有2个%@字符串同时存在
   NSLog(@"%@",str2);

   //字符串赋值，参数只有一个
   NSString *str3 = [NSString stringWithString:@"参数只能有一个字符串"];
   NSLog(@"%@",str3);

   //字符串转换为utf-8格式 参数为字符串类型
   NSString *originstr = @"中文和english";
   NSString *str4 = [NSString stringWithUTF8String:[originstr cStringUsingEncoding:NSUTF8StringEncoding]];
   NSLog(@"%@",str4);

   //char*类型转换为utf-8格式
   char *charstr = "char str";
   NSString *str5 = [NSString stringWithUTF8String:charstr];
   NSLog(@"%@",str5);

   //原有字符串基础添加int,char*组成新的字符串
   int i = 100;
   char*c = "hello";
   NSString *tempstr = @"原始字符串";
   NSString *str6 = [tempstr stringByAppendingFormat:@"整数:%d 字符型:%s",i,c];
   NSLog(@"%@",str6);
   //temp上添加temp
   NSString *temp2 = [tempstr stringByAppendingString:tempstr];
   NSLog(@"%@",temp2);
   /**************************************************/


   /***********************字符串遍历****************/
   NSString *longstr = @"asdfjlzxcvnuiopqwer";
   int strlen = [longstr length];
   for(int t=0;t<strlen;t++)
   {
      char c = [longstr characterAtIndex:t];
      NSLog(@"字符串第%d位是%c",t,c);

   }
   /**************************************************/


   /***********************字符串比较***************/
   NSString *cstr1 = @"aaa";
   NSString *cstr2 = @"bbb";
   if([cstr1 isEqualToString:cstr2])
    {
       NSLog(@"字符相等");
    }

   if([cstr1 hasPrefix:@"aa"])
    {
       NSLog(@"cstr1字符串以aa开头");
    }
   if([cstr1 hasSuffix:@"momo"])
    {
       NSLog(@"cstr1字符串以momo结尾");
    }
   /**************************************************/

   /***********************字符串截取以及大小写变化***************************/
   NSString *teststr = @"中文and my english name is tom";
   NSString *to = [teststr substringToIndex:4]; //截取起始点到index为4之间的内容
   NSString *from = [teststr substringFromIndex:2]; //从index=2开始截取到末尾
   NSRange rang = NSMakeRange(2,10);
   NSString *fromto = [teststr substringWithRange:rang];
   NSLog(@"teststr首字母大写:%@",[teststr capitalizedString]);
   NSLog(@"teststr全部大写:%@",[teststr uppercaseString]);
   NSLog(@"teststr全部为小写:%@",[teststr lowercaseString]);
   /**************************************************/

   /*************************搜索和替换字符串*************************/
   NSString *searchstr = @"thisisatestsearchstring";
   NSString *search = @"is";
   NSRange rang2 = [searchstr rangeOfString:search];
   NSLog(@"is在searchstr中起始点的index是%d",rang2.location);
   NSLog(@"is在searchstr中的终结点的index是%d",rang2.location+rang2.length);
   //将搜索中的字符串替换成为一个新的字符串 
   NSString *replacestr = [searchstr stringByReplacingCharactersInRange:rang2 withString:@"来替换内容"];
   //将字符串中" " 全部替换成 * 
   NSString *replacespacewithstar = [searchstr stringByReplacingOccurrencesOfString:@" " withString:@"@"];


   /**************************************************/

}