if(布尔表达式1){ //分支1
java语句;
}else if(布尔表达式2){ //分支2
java语句;
}else if(布尔表达式3){
java语句;
}else if(布尔表达式4);{
java语句;
}else{
java语句;//以上条件没有一个成立的,则执行该语句
}
嵌套
if (a != "admin") {
alert('不存在');
}
else
{
if (a == "admin" && b == pwdflashlatest) {
window.location.href = "/main.shtml";
}
else {
alert('密码错误');
}
}
嵌套
if(num1>=num2){
if(num3>num1){
System.out.println("num2,num1,num3");
}else if(num3<num1){
if(num3>num2){
System.out.println("num2,num3,num1");
}else{
System.out.println("num3,num2,num1");
}
}
}else if(num1<num2){
if(num3>num2){
System.out.println("num1,num2,num3");
}else if(num3 < num2){
if(num3 > num1){
System.out.println("num1,num3,num2");
}else{
System.out.println("num3,num1,num2");
}
}
}