test020.java

public class test020
{

	public static void main(String[] args)
	{
		//if else 条件语句
		
		//语句序列中只有一条语句时,写法如下,但是不建议这样写,没有可读性
		int a = 100;
		if(a== 100)
			System.out.println("a = "  + a);
		
		//语句序列省略时，可以末尾加分号，代替花括号，依然不建议这样写，可读性差
		boolean b = false;
		if(b);
		boolean c = false;
		if(c) {}

		//
		int x = 45;
		int y = 12;
		if(x > y)
		{
			System.out.println("变量x大于变量y");
		}
		else
		{
			System.out.println("变量x小于变量y");
		}
		
		//
		int math = 95;
		int english = 56;
		if(math >= 60)
		{
			System.out.println("数学及格了");
		}
		else
		{
			System.out.println("数学不及格");			
		}
		
		if(english > 59)
		{
			System.out.println("英语及格了");
		}
		else
		{
			System.out.println("英语不及格");			
		}
		
		//三元运算符替代法
		int a1 = 5;
		int b1 = 0;
		if(a1 > 0)
		{
			b1 = a1;
		}
		else
		{
			b1 = -a1;
		}
		int a2 = 5;
		int b2 = 0;
		b2 = a2 > 0 ? a2:-a2;
		System.out.println("b1 = " + b1);
		System.out.println("b2 = " + b2);
		
		
	}

}