import java.awt.*;import java.util.*;
import java.applet.Applet;
public class Applet5 extends Applet {
Label prompt1,prompt2;
TextField input1, input2;
int num1,num2;
Vector v;
float f, sumf, endf;
public void init(){
prompt1 = new Label("里程");
input1 = new TextField(10);
prompt2 = new Label("加仑");
input2 = new TextField(10);
add(prompt1);
add(input1);
add(prompt2);
add(input2);
}
public void paint(Graphics g){
float f = num1/num2;
v.add(f);
for(int i = 0;i<v.size();i++){
sumf = (new Float(v.get(i).toString())).floatValue() + sumf;
endf = sumf/(v.size());}
g.drawString((new Float(endf)).toString(), 60, 60);
}
public boolean action(Event event, Object o){
if(event.target==input2){
num1 = Integer.parseInt(input1.getText());
num2 = Integer.parseInt(input2.getText()); repaint();
}
return true;
}
}
一个简单的程序,接受2个数字一个是公里数,一个是耗油量,程序计算出每一加仑能走多少公里,然后把数字存如向量,最后打印出平均值
import java.applet.Applet;
public class Applet5 extends Applet {
Label prompt1,prompt2;
TextField input1, input2;
int num1,num2;
Vector v;
float f, sumf, endf;
public void init(){
prompt1 = new Label("里程");
input1 = new TextField(10);
prompt2 = new Label("加仑");
input2 = new TextField(10);
add(prompt1);
add(input1);
add(prompt2);
add(input2);
}
public void paint(Graphics g){
float f = num1/num2;
v.add(f);
for(int i = 0;i<v.size();i++){
sumf = (new Float(v.get(i).toString())).floatValue() + sumf;
endf = sumf/(v.size());}
g.drawString((new Float(endf)).toString(), 60, 60);
}
public boolean action(Event event, Object o){
if(event.target==input2){
num1 = Integer.parseInt(input1.getText());
num2 = Integer.parseInt(input2.getText()); repaint();
}
return true;
}
}
一个简单的程序,接受2个数字一个是公里数,一个是耗油量,程序计算出每一加仑能走多少公里,然后把数字存如向量,最后打印出平均值
float f = num1/num2;
改成
public void paint(Graphics g){
float f =(float) num1/num2;因为num1和 num2都是整数,两个整数相除取的是整数商,如
5/2的结果是2,而不是2.5,因为5,2都是整数
而5.0/2的结果是2.5,因为5.0是double,所以结果是double型的
Label prompt1, prompt2;
TextField input1, input2;
float num1, num2;
Vector v = new Vector();
float f, sumf, endf; public void init() {
prompt1 = new Label("里程");
input1 = new TextField(10);
prompt2 = new Label("加仑");
input2 = new TextField(10); add(prompt1);
add(input1);
add(prompt2);
add(input2);
} public void paint(Graphics g) {
sumf = 0;
for (int i = 0; i < v.size(); i++) {
sumf = (Float)v.get(i) + sumf;
}
if (v.size()>0) endf = sumf / v.size();
g.drawString((new Float(endf)).toString(), 60, 60); } public boolean action(Event event, Object o) {
if (event.target == input2) {
num1 = Integer.parseInt(input1.getText());
num2 = Integer.parseInt(input2.getText());
float f = num1 / num2;
v.add(f); repaint();
}
return true;
}
}