if else在大部份编程语言中都是这样使用的，我们今天来简单的介绍一下关于jsp教程 中的if else 与多重条件判断。
<HTML>
<HEAD>
<TITLE>Using the if Statement</TITLE>
</HEAD>
<BODY>
<H1>Using the if Statement</H1>
<%
int value = 10;
if(value > 0)
out.println("Absolute value of " + value + " = " + value);
%>
</BODY>
</HTML>
简单对比
<HTML>
<HEAD>
<TITLE>Using Compound Statements</TITLE>
</HEAD>
<BODY>
<H1>Using Compound Statements</H1>
<%
int value = 10;
if(value > 0) {
out.println("The number was positive.");
out.println("Absolute value of " + value + " = " + value);
}
%>
</BODY>
</HTML>
if else
<HTML>
<HEAD>
<TITLE>Nested if Statements</TITLE>
</HEAD>
<BODY>
<H1>Nested if Statements</H1>
<%
double value = 2;
if (value != 0) {
if (value > 0)
out.println("The result = " + (1 / value));
else
out.println("Sorry, we need a positive number.");
}
%>
</BODY>
</HTML>
多个条件if else
<HTML>
<HEAD>
<TITLE>Using an if-else Ladder</TITLE>
</HEAD>
<BODY>
<H1>Using an if-else Ladder</H1>
<%
String day = "Friday";
if(day == "Monday")
out.println("It's Monday.");
else if (day == "Tuesday")
out.println("It's Tuesday.");
else if (day == "Wednesday")
out.println("It's Wednesday.");
else if (day == "Thurssday")
out.println("It's Thursday.");
else if (day == "Friday")
out.println("It's Friday.");
else if (day == "Saturday")
out.println("It's http://www.3lian.com/ Saturday.");
else if (day == "Sunday")
out.println("It's Sunday.");
%>
</BODY>
</HTML>