NSNumberFormatter 應(yīng)該可以滿足你對數(shù)據(jù)形式的一般需求
NSNumberFormatter 和NSDateFormatter 是NsFormatter的子類。
NSNumberFormatter類有個屬性numberStyle，它是一個枚舉型，設(shè)置不同的值可以輸出不同的數(shù)字格式。

1

    NSNumber *num1 = [NSNumber numberWithDouble:1234567.8369];
    // ==================== 類方法 ====================
    
    // 四舍五入的整數(shù)
    NSString *numberNoStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterNoStyle];
    // 小數(shù)形式
    NSString *numberDecimalStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterDecimalStyle];
    // 貨幣形式 -- 本地化
    NSString *numberCurrencyStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterCurrencyStyle];
    // 百分?jǐn)?shù)形式
    NSString *numberPercentStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterPercentStyle];
    // 科學(xué)計數(shù)
    NSString *numberScientificStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterScientificStyle];
    // 朗讀形式 -- 本地化
    NSString *numberSpellOutStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterSpellOutStyle];
    // 序數(shù)形式 -- 本地化
    NSString *numberOrdinalStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterOrdinalStyle];
    // 貨幣形式 -- 本地化
    NSString *numberCurrencyISOStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterCurrencyISOCodeStyle];
    // 貨幣形式 -- 本地化
    NSString *numberCurrencyPluralStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterCurrencyPluralStyle];
    // 會計計數(shù) -- 本地化
    NSString *numberCurrencyAccountingStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterCurrencyAccountingStyle];
    
    NSLog(@"No Style                  = %@",numberNoStyleStr);                
    NSLog(@"Decimal Style             = %@",numberDecimalStyleStr);           
    NSLog(@"Currency Style            = %@",numberCurrencyStyleStr);          
    NSLog(@"Percent Style             = %@",numberPercentStyleStr);           
    NSLog(@"Scientific Style          = %@",numberScientificStyleStr);        
    NSLog(@"Spell Out Style           = %@",numberSpellOutStyleStr);
    NSLog(@"Ordinal Style             = %@",numberOrdinalStyleStr);           
    NSLog(@"Currency ISO Style        = %@",numberCurrencyISOStyleStr);       
    NSLog(@"Currency plural Style     = %@",numberCurrencyPluralStyleStr);    
    NSLog(@"Currency accounting Style = %@",numberCurrencyAccountingStyleStr);

2

    // ==================== 定制 ====================
    
    NSNumberFormatter *numberFormatter = [NSNumberFormatter new];
    
    numberFormatter.numberStyle = NSNumberFormatterDecimalStyle;
    
    // 格式寬度
    numberFormatter.formatWidth = 15;
    
    // 填充符
    numberFormatter.paddingCharacter = @"?";
    
    // 填充位置
    numberFormatter.paddingPosition = kCFNumberFormatterPadBeforeSuffix;
    numberFormatter.positiveSuffix = @"元";
    
    NSLog(@"%@",[numberFormatter numberFromString:@"10000000元"]);  // 10000000
    
    // 縮放因子,你可以將一個數(shù)縮放指定比例,然后給其添加后綴,如傳入一個3000,你希望表示為3千,就要用到這個屬性
    // 防止影響后面的測試,故注掉
    //    numberFormatter.multiplier = @1000;
    
    //    NSLog(@"%@千",[numberFormatter numberFromString:@"1000"]);  // 1千
    
    //    numberFormatter.multiplier     = @0.001;
    //    numberFormatter.positiveSuffix = @"千";
    //    NSLog(@"%@",[numberFormatter stringFromNumber:@10000]);    // 10千
    
    // 機制不明確,負(fù)號,正號
    //    numberFormatter.negativeFormat = @"^";
    //    numberFormatter.positiveFormat = @"~0";
    
    // 貌似沒什么用
    numberFormatter.allowsFloats = NO;
    numberFormatter.alwaysShowsDecimalSeparator = NO;
    numberFormatter.maximum = @1000;
    numberFormatter.minimum = @100;
    
    // 小數(shù)點樣式
    numberFormatter.decimalSeparator = @".";
    
    // 零的樣式
    numberFormatter.zeroSymbol       = @"-";
    
    // 前綴和后綴
    numberFormatter.positivePrefix = @"!";
    numberFormatter.positiveSuffix = @"元";
    numberFormatter.negativePrefix = @"@";
    numberFormatter.negativeSuffix = @"虧";

3

    // 指定符號,與我們在前面類方法中說明的一致
    NSLog(@"貨幣代碼%@",numberFormatter.currencyCode);                     // 貨幣代碼USD
    NSLog(@"貨幣符號%@",numberFormatter.currencySymbol);                   // 貨幣符號$
    NSLog(@"國際貨幣符號%@",numberFormatter.internationalCurrencySymbol);   // 國際貨幣符號USD
    NSLog(@"百分比符號%@",numberFormatter.percentSymbol);                   // 百分比符號%
    NSLog(@"千分號符號%@",numberFormatter.perMillSymbol);                   // 千分號符號‰
    NSLog(@"減號符號%@",numberFormatter.minusSign);                         // 減號符號-
    NSLog(@"加號符號%@",numberFormatter.plusSign);                          // 加號符號+
    NSLog(@"指數(shù)符號%@",numberFormatter.exponentSymbol);                    // 指數(shù)符號E
    
    // 整數(shù)最多位數(shù)
    numberFormatter.maximumIntegerDigits = 10;
    
    // 整數(shù)最少位數(shù)
    numberFormatter.minimumIntegerDigits = 2;
    
    // 小數(shù)位最多位數(shù)
    numberFormatter.maximumFractionDigits = 3;
    
    // 小數(shù)位最少位數(shù)
    numberFormatter.minimumFractionDigits = 1;
    
    // 數(shù)字分割的尺寸
    numberFormatter.groupingSize = 4;
    
    // 除了groupingSize決定的尺寸外,其他數(shù)字位分割的尺寸
    numberFormatter.secondaryGroupingSize = 2;
    
    // 最大有效數(shù)字個數(shù)
    numberFormatter.maximumSignificantDigits = 12;
    
    // 最少有效數(shù)字個數(shù)
    numberFormatter.minimumSignificantDigits = 3;
    
    NSLog(@"正數(shù)%@,負(fù)數(shù)%@",[numberFormatter stringFromNumber:@(+12135230.2346)],[numberFormatter stringFromNumber:@(-12135231.2346)]);  // 正數(shù)!12,13,5230.2346元,負(fù)數(shù)@12,13,5231.2346虧
    NSLog(@"零 = %@",[numberFormatter stringFromNumber:@(0)]); //  零 = -
    
    // 舍入值,比如以10為進位值,那么156就進位為160,154進位為150
    numberFormatter.roundingIncrement = @10;
    
    // 舍入方式
    numberFormatter.roundingMode = kCFNumberFormatterRoundHalfUp;
    NSLog(@"%@",[numberFormatter stringFromNumber:@123456.7890]);  // !12,3460元