decimalNumberByRoundingAccordingToBehavior:

INDEX>Foundation>NSDecimalNumber

丸めた十進数オブジェクトを返します

Objective-C

-(NSDecimalNumber *)decimalNumberByRoundingAccordingToBehavior:(id <NSDecimalNumberBehaviors>)behavior:

Swift

解説

丸めた十進数オブジェクトを返します。
レシーバが3.141592でデフォルトの丸めを使えば3.14を返します。

返り値

Objective-C

( NSDecimalNumber * )

Swift

十進数オブジェクト

引数

Objective-C

( id <NSDecimalNumberBehaviors> )behavior

Swift

丸め方法

フレームワーク

Foundation

クラス

NSDecimalNumber

使用可能

10.0

参照

cocoaapi.hatenablog.com

例文

Objective-C

#import "MyObject.h"

@implementation MyObject

- (IBAction)myAction:(id)sender
{
NSNumberFormatter *numFormat = [[NSNumberFormatter alloc] init] ;
NSDecimalNumber *dNum1 = [[[NSDecimalNumber alloc]  initWithString:@"3.141592"] autorelease];
NSDecimalNumber *dNum = [NSDecimalNumber alloc] ;

dNum = [dNum1 decimalNumberByRoundingAccordingToBehavior:[NSDecimalNumber defaultBehavior]];

[numFormat setMaximum:dNum];
[numFormat setPositiveFormat:@"#,##0.00"];
[myOutlet setFormatter:numFormat];

NSLog([NSString stringWithFormat:@"%.2f",[[numFormat maximum] doubleValue]]);
}

@end

Swift

    //NSDecimalNumber decimalNumberByRoundingAccordingToBehavior:
    @IBAction func function022(sender: AnyObject) {
        //カスタムの丸め挙動　小数点第二位でRoundPlain
        let behavior : NSDecimalNumberHandler = NSDecimalNumberHandler(roundingMode: NSRoundingMode.RoundPlain, scale: 2, raiseOnExactness: false, raiseOnOverflow: false, raiseOnUnderflow: false, raiseOnDivideByZero: false)
        
        let dNum1 : NSDecimalNumber =
        NSDecimalNumber(string: "3.141592")
        let dNum : NSDecimalNumber = dNum1.decimalNumberByRoundingAccordingToBehavior(behavior)
        let numFormat : NSNumberFormatter = NSNumberFormatter()
        numFormat.minimum = dNum    //最小値が3.14000
        numFormat.positiveFormat = "#,##0.000000"
        textField.formatter = numFormat
        NSLog("%f",numFormat.minimum!.floatValue)
        commentLabel.stringValue = "←最小値が3.14000"
    }

編集時のバージョン

OS X 10.11
Swift2.0