GitHub Demo: https://github.com/BaHui/BigNumber
简介
<ethers>开源框架中摘录的BigNumber类, 用于
大整数的运算和比较 , 稍作整理, 去除了业务上面的代码模块. 改为较为通用的BigNumber类, 继承自NSObject.
场景
在特定场景下, 基本数据类型的运算可能已经满足不了需求了, 为了避免数据的隐式转换, 那么就需要
大数的运算了. 了解下基本数据类型的取值范围:
int:2147483648～2147483647
unsigned int:0～4294967295
unsigned long:0～4294967295
long:2147483648～2147483647
long long：-9223372036854775808～9223372036854775807
unsigned long long:1844674407370955161
__int64：-9223372036854775808～9223372036854775807
unsigned __int64：18446744073709551615
接口声明
@interface BigNumber : NSObject
// ** Constant Values **
+ (BigNumber *)constantNegativeOne;
+ (BigNumber *)constantZero;
+ (BigNumber *)constantOne;
+ (BigNumber *)constantTwo;
// ** Init Methods **
+ (instancetype)bigNumberWithDecimalString:(NSString *)decimalString;
+ (instancetype)bigNumberWithNumber:(NSNumber *)number;
+ (instancetype)bigNumberWithInteger:(NSInteger)integer;
// ** Calculate Methods **
- (BigNumber *)add:(BigNumber *)other;
- (BigNumber *)sub:(BigNumber *)other;
- (BigNumber *)mul:(BigNumber *)other;
- (BigNumber *)div:(BigNumber *)other;
- (BigNumber *)mod:(BigNumber *)other;
// ** Compare Methods **
- (BOOL)equalTo:(BigNumber *)other;
- (BOOL)lessThan:(BigNumber *)other;
- (BOOL)lessThanEqualTo:(BigNumber *)other;
- (BOOL)greaterThan:(BigNumber *)other;
- (BOOL)greaterThanEqualTo:(BigNumber *)other;
@end
使用姿势
BigNumber *firstBigNumber = [BigNumber bigNumberWithDecimalString:@"321641232112"];
BigNumber *secondBigNumber = [BigNumber bigNumberWithNumber:@(999424241)];
// 加
BigNumber *addResult = [firstBigNumber add:secondBigNumber];
NSLog(@"addResult: %@", addResult.decimalString);// 输出: 322640656353
// 减
BigNumber *subResult = [firstBigNumber sub:secondBigNumber];
NSLog(@"subResult: %@", subResult.decimalString);// 输出: 320641807871
// 乘
BigNumber *mulResult = [firstBigNumber mul:secondBigNumber];
NSLog(@"mulResult: %@", mulResult.decimalString);// 输出: 321456044277840426992
// 除
BigNumber *divResult = [firstBigNumber div:secondBigNumber];
NSLog(@"divResult = %@", divResult.decimalString);// 输出: 321
// 余
BigNumber *modResult = [firstBigNumber mod:secondBigNumber];
NSLog(@"modResult = %@", modResult.decimalString);// 输出: 826050751
// 比较
BOOL isEqual = [firstBigNumber isEqualTo:secondBigNumber];
NSLog(@"是否相等: %@", isEqual ? @"相等" : @"不相等");// 输出: 不相等
BOOL isFirstLessThanEqualToSecondNumber = [firstBigNumber lessThanEqualTo:secondBigNumber];
NSLog(@"大小比较: %@", isFirstLessThanEqualToSecondNumber ? @"不大于" : @"大于");// 输出: 大于
