JAVA编写简易计算器

最近老是布置了JAVA课后作业，自己编写一个简易计算器，本渣渣利用为数不多的JAVA知识，写下了这个真的极其简易的计算器。。。

先展示一下运行效果

可惜这个计算器如果要计算，只能按照先后顺序进行运算，不能自动分辨+-*/的运算顺序，下面上代码

package p1;import java.awt.*;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.*;@SuppressWarnings("serial")public class JSQdeg extends JFrame {int sum = 0;int f=0;String t2;String l="";char ch = ' ';//当前字符int k=0;JButton jbt[][] = new JButton[4][4];JTextField t1 = new JTextField(20);public JSQdeg() {t1.setEditable(false);GridLayout gridLayout = new GridLayout(4,0); // 创建网格布局管理器对象       gridLayout.setHgap(5); // 设置组件的水平间距        gridLayout.setVgap(5); // 设置组件的垂直间距        JPanel panel = new JPanel(); // 获得容器对象        panel.setLayout(gridLayout); // 设置容器采用网格布局管理器        this.add(panel, BorderLayout.CENTER);String name[][] = {{"1","2","3","+"},{"4","5","6","-"},{"7","8","9","*"},{"AC","0","=","/"}};for(int i = 0;i<4;i++) {for(int j = 0;j<4;j++) {jbt[i][j] = new JButton(name[i][j]);jbt[i][j].addActionListener(new ActionLis());panel.add(jbt[i][j]);}}this.add(BorderLayout.CENTER,panel);this.add(BorderLayout.NORTH,t1);this.setVisible(true);this.setSize(350, 200);}class ActionLis implements ActionListener{public void actionPerformed(ActionEvent e) {JButton b = (JButton) e.getSource();t2 = b.getText();if(t2 == "AC") {t1.setText(" ");l = "";ch = ' ';sum = 0;k = 0;}else {switch(t2){case "+":case "-":case "*":case "/": changech(t2);break;case "=": jieguo(t2);break;default : getsum(); break;}}}private void getsum() {if(ch == ' ') {l += t2;t1.setText(l);sum = Integer.parseInt(l);}else {l += t2;t1.setText(l);k = Integer.parseInt(l);}}}private void jieguo(String t2) {switch(ch){case '+':sum += k;break;case '-':sum -= k;break;case '*':sum *= k;break;case '/':sum /= k;break;}l = String.valueOf(sum);t1.setText(l);l = "";ch = ' ';sum = 0;k = 0;f = 0;}public static void main(String[] args) {new JSQdeg();}public void changech(String t22) {switch(ch){case '+':sum += k;break;case '-':sum -= k;break;case '*':sum *= k;break;case '/':sum /= k;break;}ch = t22.charAt(0);l = String.valueOf(sum);t1.setText(l);l = "";}}

这个计算器由于并不能自动分辨计算顺序，所以在计算上还是有点LOW的，后来想起来，曾经用C语言写过一次计算器，而且是可以计算先后顺序的，便把这段C语言稍加更改之后，放入了程序中，瞬间，计算器就变得很完美了

附上代码

package p1;import java.awt.*;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.*;@SuppressWarnings("serial")public class JSQdeg extends JFrame {JButton jbt[][] = new JButton[4][4];JTextField t1 = new JTextField(20);JButton ac = new JButton("AC");String s2 = "";String textname;public JSQdeg() {t1.setEditable(false);GridLayout gridLayout = new GridLayout(4,0); // 创建网格布局管理器对象        gridLayout.setHgap(5); // 设置组件的水平间距        gridLayout.setVgap(5); // 设置组件的垂直间距        JPanel panel = new JPanel(); // 获得容器对象        panel.setLayout(gridLayout); // 设置容器采用网格布局管理器        this.add(panel, BorderLayout.CENTER);String name[][] = {{"1","2","3","+"},{"4","5","6","-"},{"7","8","9","*"},{"CE","0","=","/"}};//预先设定按钮名称for(int i = 0;i<4;i++) {for(int j = 0;j<4;j++) {jbt[i][j] = new JButton(name[i][j]);//将按钮名称添加到按钮上jbt[i][j].addActionListener(new ActionLis());//给按钮添加监听器jbt[i][j].setBackground(Color.cyan);//设置按钮背景颜色jbt[i][j].setForeground(Color.DARK_GRAY);//设置按钮字体颜色jbt[i][j].setFont(new Font("宋体", Font.PLAIN, 16));//设置按钮字体样式大小panel.add(jbt[i][j]);//将按钮添加到面板上}}ac.addActionListener(new ActionLis());ac.setBackground(Color.cyan);//设置按钮背景颜色ac.setForeground(Color.red);//设置按钮字体颜色ac.setFont(new Font("宋体", Font.PLAIN, 16));//设置按钮字体样式大小this.add(BorderLayout.CENTER,panel);this.add(BorderLayout.NORTH,t1);this.add(BorderLayout.SOUTH,ac);this.setVisible(true);this.setSize(350, 200);}class ActionLis implements ActionListener{@SuppressWarnings("null")public void actionPerformed(ActionEvent e) {JButton b = (JButton) e.getSource();String btname = b.getText();if(btname == "="){double a[] = new double[1000];int i,k,s,f = 0;k=0;        int l = s2.length();        s2 += "@";        for(i=0; i<l;) {            if(s2.charAt(i)>='0'&&s2.charAt(i)<='9') {                s=0;                while(s2.charAt(i)>='0'&&s2.charAt(i)<='9') {                    s*=10;                    s+=s2.charAt(i)-'0';                    i++;                }                a[k]=s;                k++;            }            switch(s2.charAt(i)) {            case '+': a[k] = -1;k++;i++;break;            case '-': a[k] = -2;k++;i++;break;            case '*': a[k] = -3;k++;i++;break;            case '/': a[k] = -4;k++;i++;break;            }        }        for(i=0; i<k; i++) {            if(a[i]==-3||a[i]==-4) {                if(a[i]==-3) {                    a[i+1]=(a[i-1]*a[i+1]*1.0);                    a[i-1]=-5;                    a[i]=-5;                }                if(a[i]==-4) {                    a[i+1]=a[i-1]/a[i+1]*1.0;                    a[i-1]=-5;                    a[i]=-5;                }            }        }        double s1 = 0;        for(i=0;i<k;i++) {            if(a[i]!=-5) {                s1=a[i];                break;            }        }        for(i=1; i<k;) {            if(a[i]==-1||a[i]==-2) {                if(a[i]==-1)                    f=1;                else                    f=2;                i++;            }            if(f==1&&a[i]!=-5)                s1+=a[i];            if(f==2&&a[i]!=-5)                s1-=a[i];            i++;        }        textname = Double.toString(s1);        t1.setText(textname);        s2 = "";}else if(btname == "CE") {int l = s2.length();s2 = s2.substring(0,l-1);        t1.setText(s2);}else if(btname == "AC") {s2 = " ";        t1.setText(s2);}else{s2 += btname;t1.setText(s2);}}}public static void main(String[] args) {new JSQdeg();}}