objective-c中的NSString操作
//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=@"ThisisaString!";
NSLog(@"astring:%@",astring);
[astring release];//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=[[NSStringalloc]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;
intj=2;
NSString*astring=[[NSStringalloc]initWithString:[NSStringstringWithFormat:@"%d.Thisis%istring!",i,j]];
NSLog(@"astring:%@",astring);
[astring release];//6、创建临时字符串
NSString *astring;
astring=[NSStringstringWithCString:"Thisisatemporarystring"];
NSLog(@"astring:%@",astring);NSString*path=@"astring.text";
NSString*astring=[[NSStringalloc]initWithContentsOfFile:path];
NSLog(@"astring:%@",astring);
[astring release];NSString*astring=[[NSStringalloc]initWithString:@"ThisisaString!"];
NSLog(@"astring:%@",astring);
NSString*path=@"astring.text";
[astringwriteToFile:pathatomically:YES];
[astring release];//用C比较:strcmp函数
char string1[] = "string!";
charstring2[]="string!";
if(strcmp(string1,string2)==0)
{
NSLog(@"1");
}//isEqualToString方法
NSString*astring01=@"ThisisaString!";
NSString*astring02=@"ThisisaString!";
BOOLresult=[astring01isEqualToString:astring02];
NSLog(@"result:%d",result);//compare方法(comparer返回的三种值)
NSString*astring01=@"ThisisaString!";
NSString*astring02=@"ThisisaString!";
BOOLresult=[astring01compare:astring02]==NSOrderedSame;
NSLog(@"result:%d",result);//NSOrderedSame 判断两者内容是否相同
NSString *astring01 = @"This is a String!";
NSString*astring02=@"thisisaString!";
BOOL result = [astring01 compare:astring02] = = NSOrderedAscending;NSLog(@"result:%d",result);
//NSOrderedAscending 判断两对象值的大小(按字母顺序进行比较，astring02大于astring01为真)
NSString *astring01 = @"this is a String!";
NSString*astring02=@"ThisisaString!";
BOOLresult=[astring01compare:astring02]==NSOrderedDescending;
NSLog(@"result:%d",result);//NSOrderedDescending 判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)
//不考虑大 小写比较字符串1
NSString*astring01=@"thisisaString!";
NSString*astring02=@"ThisisaString!";
BOOLresult=[astring01caseInsensitiveCompare:astring02]==NSOrderedSame;
NSLog(@"result:%d",result);//NSOrderedDescending判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)
//如何判断字符串为空
NSString *urlString = [urlInput stringValue];
if(!urlString){
NSLog( @”NO INPUT.” );
}else{
if ([urlString length] == 0 ) {NSLog( @”NO INPUT.” );
} else {
}
}
}Convert NSString to int
1 | NSString *aNumberString = @"123"; |
2 | int i = [aNumberString intValue]; |
Convert int to NSString
1 | int aNumber = 123; |
2 | NSString *aString = [NSString stringWithFormat:@"%d", aNumber]; |