java筆記0x002：操作符

liaoyg8023 發(fā)布于2019-08-15 15:47 / 3325人閱讀

摘要：算數(shù)運(yùn)算符自增自減關(guān)系操作符邏輯操作符直接操作符三元運(yùn)算符字符串類(lèi)型轉(zhuǎn)化轉(zhuǎn)化會(huì)被舍去轉(zhuǎn)化會(huì)被舍去

0x001 算數(shù)運(yùn)算符

        int num1 = 1, num2 = 2;
        System.out.println(num1 + num2); // 3
        System.out.println(num1 - num2); // -1
        System.out.println(num1 / num2); // 0 
        System.out.println(num1 * num2); // 2
        System.out.println(num1 % num2); //1

0x002 自增自減

        System.out.println(num1++); // 1
        System.out.println(num1); // 2
        System.out.println(num1--); // 2
        System.out.println(num1); // 1
        System.out.println(++num1); // 2
        System.out.println(--num1); // 1

0x003 關(guān)系操作符

        System.out.println((num1 < num2)); // true
        System.out.println((num1 > num2)); // false
        System.out.println(num1 == num2); // false
        System.out.println(num1 != num2); // true

0x004 邏輯操作符

        boolean boolean1 = false; 
        boolean boolean2 = true; 
        System.out.println(boolean1 && boolean2); // false
        System.out.println(boolean1 || boolean2); // true
        System.out.println(!boolean1); // true

0x005 直接操作符

        int i1 = 0x2f;
        int i2 = 0x2F;
        int i3 = 0177;
        char c1 = 0xffff;
        byte b1 = 0x7f;
        short s1 = 0x7f;
        long l1 = 100L;
        long l2 = 100l;
        float f1 = 1;
        float f2 = 1f;
        float f3 = 1F;
        double d1 = 1d;
        double d2 = 1D;
        System.out.println(i1); // 47
        System.out.println(i2); //47
        System.out.println(i3); // 127
        System.out.println(c1); // 
        System.out.println(b1); // 127
        System.out.println(s1); // 127
        System.out.println(l1); // 100
        System.out.println(l2); // 100
        System.out.println(f1); // 1.0
        System.out.println(f2); // 1.0
        System.out.println(f3); // 1.0
        System.out.println(d1); // 1.0
        System.out.println(d2); // 1.0

0x006 三元運(yùn)算符

        int a = 0;
        boolean isSuccess = false;
        a = isSuccess ? 1 : 2;
        System.out.println(a);// 2

0x007 字符串+、+=

        String str = "";
        str = str + "1";
        str +=  "2";
        System.out.println(str);

0x008 類(lèi)型轉(zhuǎn)化

        int i = 100;
        long long1 = (long) i;
        System.out.println(long1);// 100
        long1 = i;
        System.out.println(long1);// 100
        long long2 = (long) 200;
        System.out.println(long2);// 200
        i = (int) long1;
        System.out.println(i); // 200
        
        float float1=0.1f; 
        float float2=0.9f;
        System.out.println((int) float1);// 轉(zhuǎn)化int會(huì)被舍去
        System.out.println((int) float2);// 轉(zhuǎn)化int會(huì)被舍去