[基础]NSString与NSMutableString字符串操作：增、删、改字符串

 NSString是定义固定大小的字符串，NSMutableString可变，可对字符串做增、删、改、插入等操作。
 源代码strings.m
 -----------------------------------
 #import <Foundation/Foundation.h>
 int main (int argc, const char * argv[]) {
     NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
     // insert code here...
     NSString *artist = @"Underworld";
 NSLog(@"The \"%@\" length is %d",artist,[artist length]);

 NSString *substring = [artist substringFromIndex:5];

     NSLog(@"From index 5 to end that substring is \"%@\"",substring);

 NSRange range = [artist rangeOfString:@"w"];
 NSLog(@"range.location = %d,是字母\"w\"所在的索引位置",range.location);
 NSLog(@"range.length = %d,是字母\"w\"的长度",range.length);

 NSLog(@"------------------------------");

 NSString *song = @"美丽新世界,伍佰";
 NSRange range1 = [song rangeOfString:@","];
 NSString *songName = [song substringToIndex:range1.location];
 NSString *songAuthor = [song substringFromIndex:range1.location + range1.length]; //如果不加上range1.length,取词就包含逗号

 NSLog(@"歌曲:%@",song);
 NSLog(@"\",\"号位置为 %d",range1.location);
 NSLog(@"歌名:%@",songName);
 //printf("歌名:%s \n",[songName UTF8String]);//正确
 //NSLog(@"歌名:%@", [songName UTF8String]);//错误
 NSLog(@"作者:%@",songAuthor);

 NSLog(@"---------------------------------");
 NSLog(@"可变字符串类NSMultableString演示:");

 NSMutableString *movie = [[NSMutableString alloc] initWithString:@"变形金刚2"];

 NSLog(@"%@",movie);

 [movie appendString:@",派拉蒙影业"];
 NSLog(@"%@.方法appendString",movie);

 NSRange range2 = [movie rangeOfString:@"派拉蒙影业"];
 [movie replaceCharactersInRange:range2 withString:@"派拉蒙电影公司"]; //不是range2.location
 NSLog(@"%@.方法replaceCharactersInRange",movie);

 [movie deleteCharactersInRange:[movie rangeOfString:@"公司"]];
 NSLog(@"%@.方法deleteCharactersInRange",movie);

     range2 = [movie rangeOfString:@"变形金刚"];
 [movie insertString:@"科幻电影:" atIndex:range2.location];
 NSLog(@"%@.方法insertString",movie);

 [movie release]; //采用alloc的对象都不要忘记release
 [pool drain];
     return 0;
 }