public class Testfun {

public static void main(String[] args) {

// (一)跨Number父類的類型轉換

// 1、str轉int => Integer.parseInt(s1)

String s1 = "19";

int i2 = Integer.parseInt(s1);// 數字str轉化為對標的int

System.out.println("++i2=" + (++i2));

// 2、int轉str => Integer.toString(i3)

int i3 = 27;

String s4 = Integer.toString(i3);

System.out.println("s4=" + s4);

// 3、浮點轉int => (int) d5

double d5 = 21.6;

int i6 = (int) d5;

System.out.println("i6=" + i6);

// 4、int轉浮點 => (double) i7

int i7 = 60;

double d8 = (double) i7;

System.out.println("d8=" + d8);

// (二)同Number父類的類型轉換

System.out.println();

Integer i9 = new Integer("17");

System.out.println(i9.intValue()); // 數字str轉為int => i9.intValue()

System.out.println(i9.shortValue());// 數字str轉為short => i9.shortValue()

System.out.println(i9.byteValue());// 數字str轉為byte => i9.byteValue()

System.out.println();

// int轉str(不同進制形式的str)

System.out.println(Integer.toString(456)); //獲取10進制str

System.out.println(Integer.toBinaryString(456)); //獲取2進制str

System.out.println(Integer.toHexString(456)); //獲取16進制str

System.out.println(Integer.toOctalString(456)); //獲取8進制str

}

}