实验报告 编写一个简易实用的计算器。

开课实验室：现代信息交流中心40*开课时间:2012年**月**日实验报告:年月日

一、实验目的：熟悉Java图形用户界面的开发原理与技术，包括各种组件和容器技术。

二、实验内容：

编写一个简易实用的计算器。

三、源代码清单：

package exp3;

import Result extends Panel {

TextField tf;

Result() {

tf = new TextField("0", 25);

add(tf);

}

}

class Key extends Panel {

Button backSpace, clearEnter, cancel,lBracket,rBracket;

Button one, two, three, four, five, six, seven, eight, nine, zero;

Button add, subtract, multiplay, divide;

Button sqrt, reciprocal, mod;

Button positiveAndNegative, point, equal;

Key() {

setLayout(new GridLayout(5, 5));

backSpace = new Button("←");

(new Color(255, 0, 0));

add(backSpace);

clearEnter = new Button("CE");

(new Color(255, 0, 0));

add(clearEnter);

cancel = new Button("C");

(new Color(255, 0, 0));

add(cancel);

lBracket =new Button("(");

add(lBracket);

rBracket =new Button(")");

add(rBracket);

seven = new Button("7");

add(seven);

eight = new Button("8");

add(eight);

nine = new Button("9");

add(nine);

divide = new Button("/");

add(divide);

sqrt = new Button("sqrt");

add(sqrt);

four = new Button("4");

add(four);

five = new Button("5");

add(five);

six = new Button("6");

add(six);

multiplay = new Button("*");

add(multiplay);

mod = new Button("%");

add(mod);

one = new Button("1");

add(one);

two = new Button("2");

add(two);

three = new Button("3");

add(three);

subtract = new Button("-");

add(subtract);

reciprocal = new Button("1/x");

add(reciprocal);

zero = new Button("0");

add(zero);

positiveAndNegative = new Button("+/-");

add(positiveAndNegative);

point = new Button(".");

add(point);

add = new Button("+");

add(add);

equal = new Button("=");

add(equal);

}

}

public class Calculator extends Applet implements ActionListener { Result result = new Result();

Key key = new Key();

boolean isInit = true;

String operation = "";

float theFirstNum = 0;

float theSecondNum = 0;

float f = 0; == -1) {

+ ".");

isInit = false;

}

}

if () == {

theFirstNum = operation = "add";

isInit = true;

}

if () == {

theFirstNum = operation = "subtract";

isInit = true;

}

if () == {

theFirstNum = operation = "multiplay";

isInit = true;

}

if () == {