java - 压入堆栈的字符值具有不同的值

Question

大家。 我需要将字符值放入堆栈中:

        for(char ch: operand.toCharArray()) {
        System.out.println("ch: " + ch);
        numericsOfTheOperand.push((int) ch);
        System.out.println("numericsOfTheOperand.peek() " + numericsOfTheOperand.peek());
    }

例如，操作数:456454 控制台输出:

ch: 4
numericsOfTheOperand.peek() 52
ch: 5
numericsOfTheOperand.peek() 53
ch: 6
numericsOfTheOperand.peek() 54
ch: 4
numericsOfTheOperand.peek() 52
ch: 5
numericsOfTheOperand.peek() 53
ch: 4
numericsOfTheOperand.peek() 52
ch: 4
numericsOfTheOperand.peek() 52

我不明白，为什么值不同？ 我该如何解决？

Answer 1

要将 char 推送到 Stack，您需要将其声明为:

Stack<Character> numericsOfTheOperand = new Stack<>();

然后你就可以做你的事情了:

String operand = "456454";
for(char ch: operand.toCharArray()) {
    numericsOfTheOperand.push(ch);
    System.out.println("numericsOfTheOperand.peek() " + numericsOfTheOperand.peek());
}

输出:

numericsOfTheOperand.peek() 4
numericsOfTheOperand.peek() 5
numericsOfTheOperand.peek() 6
numericsOfTheOperand.peek() 4
numericsOfTheOperand.peek() 5
numericsOfTheOperand.peek() 4

您将 char 转换为 int，从而获得它的 int 值。