Question

'ans'字符串包含“55/42 =”（假设）。我正在尝试计算这个字符串的答案并将其存储在'ans'本身。请在代码中指出我的错误。

public void equalto() {
    int i, j, ltemp2;
    String temp1 = "", temp2 = "", temp2rev = "", temp3 = "";
    char temp;
    double temp11, temp22, temp33;
    for (i = 0; ans.charAt(i) != '='; i++) {
        if (ans.charAt(i) == '/') {
            j = i + 1;
            while (ans.charAt(j) != '+' || ans.charAt(j) != '-' || ans.charAt(j) != '*' || ans.charAt(j) != '/' || ans.charAt(j) != '=') {
                temp = ans.charAt(j);
                temp1 = temp1 + temp;
                j++;
            }
            j = i - 1;
            while ((j >= 0) && (ans.charAt(j) != '+' || ans.charAt(j) != '-' || ans.charAt(j) != '*' || ans.charAt(j) != '/')) {
                temp = ans.charAt(j);
                temp2 = temp2 + temp;
                j--;
            }
        }
    }
    ltemp2 = temp2.length();   //For reversing the temp2
    for (j = ltemp2 - 1; j >= 0; j--)
        temp2rev = temp2rev + temp2.charAt(j);
    temp11 = Double.parseDouble(temp1);
    temp22 = Double.parseDouble(temp2rev);   //temp2rev is the actual string. temp2 is in the reversed form.
    temp33 = temp22 / temp11;
    temp3 = String.valueOf(temp33);
    ans = ans.replaceFirst(temp2rev + "/" + temp1 + "=", temp3);
}

Answer 1

while(ans.charAt(j)!='+' || ...
while((j>=0)&&(ans.charAt(j)!='+' || ...

替换所有||与＆amp;＆amp;

temp2=temp2+temp;

直接获得正确的temp2，你可以

temp2 = temp + temp2;

这个Java代码有什么错误？

1 个答案: