原值:2.7999999999 typedef CF_ENUM(CFIndex, CFNumberFormatterRoundingMode) { kCFNumberFormatterRoundCeiling = 0,//四舍五入,直接輸出3 kCFNumberFormatterRoundFloor = 1,//保留小數輸出2.8 kCFNumberFormatterRoundDown = 2,//加上了人民幣標志,原值輸出¥2.8 kCFNumberFormatterRoundUp = 3,//本身數值乘以100后用百分號表示,輸出280% kCFNumberFormatterRoundHalfEven = 4,//輸出2.799999999E0 kCFNumberFormatterRoundHalfDown = 5,//原值的中文表示,輸出二點七九九九。。。。 kCFNumberFormatterRoundHalfUp = 6//原值中文表示,輸出第三 }; NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init]; formatter.numberStyle = kCFNumberFormatterRoundHalfDown; NSString *string = [formatter stringFromNumber:[NSNumber numberWithInt:12]]; NSLog(@"str = %@", string);