变量的使用
public class Demo03Var{public static void main（string[] args）{//byetbyet num1 = 100;System.out.println(num1);//shortbyet num2 = 1000;num2 = 1001;System.out.println(num2);//int 整数的默认类型int num3 = 10000;num3 = 1;System.out.println(num3);//long->定义long型的变量后面加一个Llong num4 = 10L;System.out.println(num4);//float->定义float型变量的时候加一个Ffloat num5 = 2.5F;System.out.println(num5);//double小数的默认类型double num6 = 2.5;System.out.println(num6);//charchar num7 = 'A'System.out.println(num7);//boolenboolen num8 = true;boolen num9 = false;/*num9 = falsenum8 =num9 ->将num9的值赋值给num8 ->相当于 num8 = false*/num8=num9;System.out.println(num8);//string -> 是一个引用数据类型，属于类的一种，但是定义和基本类型一致String name = "金莲";System.out.println(name);}
}
变量的其他用法(加减乘除)
public class Demo03Var{public static void main（string[] args）{int num1 = 10;int num2 = 3;int sum = sum1+sum2;System.out.println(sum);//13int sub = num1-num2;System.out.println(sub);//7//System.out.println(num1*num2);//30int mul = num1*num2;//30/*由于/前后都是整数，结果取整数部分，结果还赋值给一个整数变量*/int div = num1/num2;System.out.println(div);//3double div1 = num1/num2;System.out.println(div);/3.0}
}