String r = “3 + 6 =”;
String[] str = r.split("");
int a = Integer.parseInt(str[0]);
int b = Integer.parseInt(str[2]);
int c = 0;
if(str[1].equals("+")){
c = a+b;
}else if(str[1].equals("-")){
c = a-b;
}else if(str[1].equals("*")){
c = a*b;
}
str[3] = String.valueOf(c);
System.out.println(str[0]+str[1]+str[2]+str[3]);
Exception in thread "main" java.lang.NumberFormatException: For input string: "+"
at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.base/java.lang.Integer.parseInt(Integer.java:642)
at java.base/java.lang.Integer.parseInt(Integer.java:770)
at pack.Solution.main(Solution.java:29)
我的方式报错了。
