Question

我想计算字符串，如：

＆＃34; -4443- + 397＆＃34; //应该返回-4840

＆＃34; -8844443 / -73897＆＃34; //应该返回119

＆＃34; 4433 * -7＆＃34; //应返回-31038

＆＃34; +4 * -5897＆＃34; //应该返回-23588

它非常困难和棘手，我不应该如何计算字符串。问题不是删除空白，更多的是我应该如何计算上面的字符串。：（

public static int calc(String input) {

    String noSpaces = "";
    int i = 0;

    while (i < input.length()) {
        if (input.charAt(i) != ' ') {
            noSpaces = input.charAt(i);
        }
        i++;
 }

Answer 1

这仅适用于一个数字

公共类计算器{

static int calc(String input) {
    String nsp = "";
    int nr1;
    int nr2;
    char op;
    int result = 0;

    for (int i = 0; input.length() > i; i++) {

        if (input.charAt(i) != ' ') {
            nsp = nsp + input.charAt(i);
        }

    }

    if (nsp.charAt(0) == '+' || nsp.charAt(0) == '-') {
        nr1 = Integer.parseInt(nsp.substring(0, 2));
        op = nsp.charAt(2);
        if (nsp.charAt(3) == '+' || nsp.charAt(3) == '-') {
            nr2 = Integer.parseInt(nsp.substring(3, 5));
        } else {
            nr2 = Integer.parseInt(nsp.substring(3, 4));
        }
    } else {
        nr1 = Character.getNumericValue(nsp.charAt(0));
        op = nsp.charAt(1);
        if (nsp.charAt(2) == '+' || nsp.charAt(2) == '-') {
            nr2 = Integer.parseInt(nsp.substring(2, 4));
        } else {
            nr2 = Integer.parseInt(nsp.substring(2, 3));
        }
    }

    if (op == '+') {
        result = nr1 + nr2;
    }

    if (op == '-') {
    result = nr1 - nr2;
     }

    if (op == '*') {
        result = nr1 * nr2;
    }

    if (op == '/') {
        result = nr1 / nr2;
    }

    return result;
}

}

用Java计算字符串，很棘手

1 个答案: