NSString到NSNumber

Question

所以这个问题已经困扰我太久了。我有一个包含textField的UIAlertView，我需要将textField的值作为NSNumber。但我尝试的每一件事都会得到随机的数字串。任何帮助都将不胜感激。

int i = [[alertView textFieldAtIndex:0].text intValue];
NSNumber *number = [NSNumber numberWithInt:[[alertView textFieldAtIndex:0].text integerValue]];    


int number = [[dict objectForKey:@"integer"] intValue];

NSLog(@"text = %@", [alertView textFieldAtIndex:0].text);


NSString *alertText = [alertView textFieldAtIndex:0].text;

NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterNoStyle];
NSNumber * myNumber = [f numberFromString:[alertView textFieldAtIndex:0].text];


NSNumber *number = @([alertText intValue]);

NSString *string = @"54";
NSNumber *number = @([string intValue]);

NSLog(@"here we are: %i", number);

Answer 1

一旦看到这张照片，

NSString *string = @"123";
NSNumber  *aNum = [NSNumber numberWithInteger: [string integerValue]];
NSLog(@"%@",aNum);//NSString to NSNumber
NSInteger number=[string intValue];
NSLog(@"%i",number);//NSString to NSInteger

Answer 2

NSString *string = @"54";
NSNumber *number = @([string intValue]);
NSLog(@"here we are: %i", number);

请尝试使用以下命令：

NSLog(@"here we are: %@", number);

因为您要转换为NSNumber (Object)。您应该在NSLog语句中使用对象说明符%@。

Answer 3

下面是一个包含整数并使用NSNumber字面量的示例。如果字符串包含浮点数，也可以使用floatValue方法。

NSString *string = @"54";
NSNumber *number = @([string intValue]);