运用String类的相关方法写的简单的计算器
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String str = scanner.next();
int i = str.indexOf('+');
scanner.close();
if(i != -1)
{
System.out.println(new calcu().check("+",str,i));
return;
}
i = str.indexOf('-');
if (i != -1) {
System.out.println(new calcu().check("-",str,i));
return;
}
i = str.indexOf('*');
if (i != -1) {
System.out.println(new calcu().check("*",str,i));
return;
}
i = str.indexOf('/');
if (i != -1) {
System.out.println(new calcu().check("/",str,i));
return;
}
}
public int left(String a,int i) {
int l = Integer.parseInt(a.substring(0,i));
return l;
}
public int right(String a,int i) {
int r = Integer.parseInt(a.substring(i+1));
return r;
}
public String check(String code,String str,int i) {
int sum=0;
int l,r;
l = left(str, i);
r = right(str, i);
switch (code) {
case "+":
sum = l + r;
break;
case "-":
sum = l - r;
break;
case "*":
sum = l * r;
break;
case "/":
if(r != 0 ){
sum = l / r;
}
else {
return "错误!被除数不能为0";
}
break;
}
return str + " = " + sum;
}
希望可以和大家互相学习,谢谢大家!!!