Java int、Integer与BigInteger类型之间的转换

一、int与Integer之间的转换

1.int转Integar

int a = 3;
Integer b = a;
System.out.print(b);

2.Integar转int

Integer a = 3;
int b = a;
System.out.print(b);

二、Integer与BigInteger之间的转换

1.Integer转BigInteger

Integer a = 3;
BigInteger b = new BigInteger(String.valueOf(a));
System.out.print(b);

2.BigInteger转Integer

BigInteger a = new BigInteger("3");
Integer b = a.intValue();
System.out.print(b);

三、int与BigInteger之间的转换

1.int转BigInteger

int a = 3;
BigInteger b = new BigInteger(String.valueOf(a));
System.out.print(b);

2.BigInteger转int

BigInteger a = new BigInteger("3");
int b = a.intValue();
System.out.print(b);

补充：BigInteger转BigDecimal

BigInteger a = new BigInteger("3");
BigDecimal b = new BigDecimal(a);
System.out.print(b);

本文输出均为3