[Java手记]条件语句 if...else与switch case

1、if...else

判断条件是否成立决定执行哪条语句

if(1==1){
	System.out.println("1=1是真");
}else{
	System.out.println("1=1是假");
}

int a = 2;
if(a == 1){
	System.out.println("a等于1");
}else if(a == 2){
	System.out.println("a等于2");
}else if(1 == 3){
	System.out.println("a等于3");
}

2、switch case

等值判断语句

int i = 3;
switch(i){
case 0:
	System.out.println("0");
	break;
case 1:
	System.out.println("1");
	break;
case 2:
	System.out.println("2");
	break;
case 3:
	System.out.println("3"); 
	break;
default:
	System.out.println("default");
}