【iOS】NSNumberFormatter

介绍

NSNumberFormatter 应该可以满足你对数据形式的一般需求,值得了解一下.

    NSNumber *num1 = [NSNumber numberWithDouble:1234567.8369];

    // ==================== 类方法 ====================

    // 四舍五入的整数
    NSString *numberNoStyleStr                 = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterNoStyle];

    // 小数形式
    NSString *numberDecimalStyleStr            = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterDecimalStyle];

    // 货币形式 -- 本地化
    NSString *numberCurrencyStyleStr           = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterCurrencyStyle];

    // 百分数形式
    NSString *numberPercentStyleStr            = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterPercentStyle];

    // 科学计数
    NSString *numberScientificStyleStr         = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterScientificStyle];

    // 朗读形式 -- 本地化
    NSString *numberSpellOutStyleStr           = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterSpellOutStyle];

    // 序数形式 -- 本地化
    NSString *numberOrdinalStyleStr            = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterOrdinalStyle];

    // 货币形式 ISO -- 本地化
    NSString *numberCurrencyISOStyleStr        = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterCurrencyISOCodeStyle];

    // 货币形式 -- 本地化
    NSString *numberCurrencyPluralStyleStr     = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterCurrencyPluralStyle];

    // 会计计数 -- 本地化
    NSString *numberCurrencyAccountingStyleStr = [NSNumberFormatter localizedStringFromNumber:num1 numberStyle:NSNumberFormatterCurrencyAccountingStyle];

    NSLog(@"No Style                  = %@",numberNoStyleStr);                // No Style                  = 1234568
    NSLog(@"Decimal Style             = %@",numberDecimalStyleStr);           // Decimal Style             = 1,234,567.837
    NSLog(@"Currency Style            = %@",numberCurrencyStyleStr);          // Currency Style            = $1,234,567.84
    NSLog(@"Percent Style             = %@",numberPercentStyleStr);           // Percent Style             = 123,456,784%
    NSLog(@"Scientific Style          = %@",numberScientificStyleStr);        // Scientific Style          = 1.2345678369E6
    // Spell Out Style           = one million two hundred thirty-four thousand five hundred sixty-seven point eight three six nine
    NSLog(@"Spell Out Style           = %@",numberSpellOutStyleStr);
    NSLog(@"Ordinal Style             = %@",numberOrdinalStyleStr);            // Ordinal Style             = 1,234,568th
    NSLog(@"Currency ISO Style        = %@",numberCurrencyISOStyleStr);        // Currency ISO Style        = USD1,234,567.84
    NSLog(@"Currency plural Style     = %@",numberCurrencyPluralStyleStr);     // Currency plural Style     = 1,234,567.84 US dollars
    NSLog(@"Currency accounting Style = %@",numberCurrencyAccountingStyleStr); // Currency accounting Style = $1,234,567.84

    // ==================== 定制 ====================

    NSNumberFormatter *numberFormatter = [NSNumberFormatter new];

    numberFormatter.numberStyle = NSNumberFormatterDecimalStyle;

    // 格式宽度
    numberFormatter.formatWidth = 15;

    // 填充符
    numberFormatter.paddingCharacter = @"?";

    // 填充位置
    numberFormatter.paddingPosition = kCFNumberFormatterPadBeforeSuffix;
    numberFormatter.positiveSuffix = @"元";

    NSLog(@"%@",[numberFormatter numberFromString:@"10000000元"]);  // 10000000

    // 缩放因子,你可以将一个数缩放指定比例,然后给其添加后缀,如传入一个3000,你希望表示为3千,就要用到这个属性
    // 防止影响后面的测试,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

    // 机制不明确,负号,正号
//    numberFormatter.negativeFormat = @"^";
//    numberFormatter.positiveFormat = @"~0";

    // 貌似没什么用
    numberFormatter.allowsFloats = NO;
    numberFormatter.alwaysShowsDecimalSeparator = NO;
    numberFormatter.maximum = @1000;
    numberFormatter.minimum = @100;

    // 小数点样式
    numberFormatter.decimalSeparator = @".";

    // 零的样式
    numberFormatter.zeroSymbol       = @"-";

    // 前缀和后缀
    numberFormatter.positivePrefix = @"!";
    numberFormatter.positiveSuffix = @"元";
    numberFormatter.negativePrefix = @"@";
    numberFormatter.negativeSuffix = @"亏";

    // 指定符号,与我们在前面类方法中说明的一致
    NSLog(@"货币代码%@",numberFormatter.currencyCode);                     // 货币代码USD
    NSLog(@"货币符号%@",numberFormatter.currencySymbol);                   // 货币符号$
    NSLog(@"国际货币符号%@",numberFormatter.internationalCurrencySymbol);   // 国际货币符号USD
    NSLog(@"百分比符号%@",numberFormatter.percentSymbol);                   // 百分比符号%
    NSLog(@"千分号符号%@",numberFormatter.perMillSymbol);                   // 千分号符号‰
    NSLog(@"减号符号%@",numberFormatter.minusSign);                         // 减号符号-
    NSLog(@"加号符号%@",numberFormatter.plusSign);                          // 加号符号+
    NSLog(@"指数符号%@",numberFormatter.exponentSymbol);                    // 指数符号E

    // 整数最多位数
    numberFormatter.maximumIntegerDigits = 10;

    // 整数最少位数
    numberFormatter.minimumIntegerDigits = 2;

    // 小数位最多位数
    numberFormatter.maximumFractionDigits = 3;

    // 小数位最少位数
    numberFormatter.minimumFractionDigits = 1;

    // 数字分割的尺寸
    numberFormatter.groupingSize = 4;

    // 除了groupingSize决定的尺寸外,其他数字位分割的尺寸
    numberFormatter.secondaryGroupingSize = 2;

    // 最大有效数字个数
    numberFormatter.maximumSignificantDigits = 12;

    // 最少有效数字个数
    numberFormatter.minimumSignificantDigits = 3;

    NSLog(@"正数%@,负数%@",[numberFormatter stringFromNumber:@(+12135230.2346)],[numberFormatter stringFromNumber:@(-12135231.2346)]);  // 正数!12,13,5230.2346元,负数@12,13,5231.2346亏
    NSLog(@"零 = %@",[numberFormatter stringFromNumber:@(0)]); //  零 = -

    // 舍入值,比如以10为进位值,那么156就进位为160,154进位为150
    numberFormatter.roundingIncrement = @10;

    // 舍入方式
    numberFormatter.roundingMode = kCFNumberFormatterRoundHalfUp;
    NSLog(@"%@",[numberFormatter stringFromNumber:@123456.7890]);  // !12,3460元

文／刘大帅（简书作者）
原文链接：http://www.jianshu.com/p/817029422a72
著作权归作者所有，转载请联系作者获得授权，并标注“简书作者”。