ios常用字符串的操作..doc

ios 常用字符串的操作 //将NSData转化为NSStringNSString* str = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];//将NSString 转化为NSData (NSString.h)- (NSData *)dataUsingEncoding:(NSStringEncoding)encoding; //载一个字符串中删除一个字符或字符串[_display deleteCharactersInRange:NSMakeRange(index_of_char_to_remove, 1)];数学转换为字符串NSString *returnStr;returnStr = [[NSNumber numberWithInt:row] stringValue];NSString *******************************************************************************************/ //一、NSString /*----------------创建字符串的方法----------------*/ //1、创建常量字符串。 NSString *astring = @This is a String!; //2、创建空字符串，给予赋值。 NSString *astring = [[NSString alloc] init]; astring = @This is a String!; [astring release]; NSLog(@astring:%@,astring); //3、在以上方法中，提升速度:initWithString方法 NSString *astring = [[NSString alloc] initWithString:@This is a String!]; NSLog(@astring:%@,astring); [astring release]; //4、用标准c创建字符串:initWithCString方法 char *Cstring = This is a String!; NSString *astring = [[NSString alloc] initWithCString:Cstring]; NSLog(@astring:%@,astring); [astring release]; //5、创建格式化字符串:占位符（由一个%加一个字符组成） int i = 1; int j = 2; NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@%d.This is %i string!,i,j]]; NSLog(@astring:%@,astring); [astring release]; //6、创建临时字符串 NSString *astring; astring = [NSString stringWithCString:This is a temporary string]; NSLog(@astring:%@,astring); /*----------------从文件读取字符串:initWithContentsOfFile方法----------------*/ NSString *path = @astring.text; NSString *astring = [[NSString alloc] initWithContentsOfFile:path]; NSLog(@astring:%@,astring); [astring release]; /*----------------写字符串到文件:writeToFile方法----------------*/ NSString *astring = [[NSString alloc] initWithString:@This is a String!]; NSLog(@astring:%@,astring); NSString *path = @astring.text; [astring writeToFile: path atomically: YES]; [astring release]; /*----------------比较两个字符串-