用字符串连接零

Question

我试图将零附加到字符串,使其成为32位数.但输出不显示附加的零.为什么会这样？

    System.out.print("\nEnter the linear Address (32bit) :\t");
    String linear_hex= sc.nextLine();
    String linear_bin= Integer.toBinaryString(Integer.parseInt(linear_hex,16));

    if(linear_bin.length() != 32)
    {

        for(int i= linear_bin.length(); i<=32; i++)
            linear_bin= 0+linear_bin;
    }

输出:

Enter the linear Address (32bit) :  12345678
Linear Address = 10010001101000101011001111000

我也试过linear_bin= "0"+linear_bin;,"0".concat(linear_bin);但输出仍然是一样的.

Answer 1

你的代码对我来说很好:

System.out.print("\nEnter the linear Address (32bit) :\t");
    Scanner sc = new Scanner(System.in);
    String linear_hex= sc.nextLine();
    String linear_bin= Integer.toBinaryString(Integer.parseInt(linear_hex,16));

    if(linear_bin.length() != 32) {         
        // Should be i < 32 instead of i <= 32, else you end up with an extra 0
        // Also consider using StringBuilder instead of String concatenation here
        for(int i= linear_bin.length(); i < 32; i++)
            linear_bin= 0+linear_bin;
    }
    System.out.println(linear_bin);

输入:

123456

输出:

00000000000100100011010001010110

但是,您可以使用String.format()方法更轻松地实现此目的.删除if块,并添加此print语句:

System.out.println(String.format("%32s", linear_bin).replace(' ', '0'));