Arabic numerals to Chinese

Cat's eye interview questions

error ：
1.String[] Array fixed , Back res.add error , use arraylist perhaps vector Variable array
2. The number of zeros is not considered
1001 It should be onethousand and one , Code output 10011
1000 It should be a thousand , Code output 1000
The right code , as follows ：

public class NumtoHanzi {
    
	public static String convertHanzi(String a) {
    
		String [] uniform = {
    " zero "," Ten "," hundred "," thousand "};
		String [] hanzi = {
    " zero "," One "," Two "," 3、 ... and "," Four "," 5、 ... and "," 6、 ... and "," 7、 ... and "," 8、 ... and "," Nine "};
		if(a == null)
			return null;
		int len = a.length();
		int index = len - 1;
		if(a == "10")
			return " Ten ";
		int[] digit = new int[a.length()];
		int i = 0;
		String res = " ";
		while(index >= 0) {
    
			int num = Integer.parseInt(String.valueOf(a.charAt(index)));
			digit[i] = num;
			index--;
			i++;
		}
		for(int j = len - 1; j >= 0; j--) {
    
			if(digit[j] != 0) {
    
				res += hanzi[digit[j]];
				if(j != 0) {
    
					res += uniform[j];
				}
			}else {
    
				while(j >=0 && digit[j] == 0) {
    
					j--;
				}
				if(j == -1)
					break;// All are zero 
				// Zero connection is blocked 
				res += uniform[0];
				j++;// The loop itself has to j--;
			}
			
			
		}
		return res;
	}
	public static void main(String[] args) {
    
		System.out.println(convertHanzi("1011"));
	}

}

Ideas ：
First, store the number in reverse order ,1234 Save as 4321.
And then to 4321, Subscript 3 The corresponding number 1, add uniform The corresponding subscript 3 The connective thousand , When subscript is 0, No connectives .
Dealing with zero , Go straight to zero until the end , Then there is no zero , Such as 1000 perhaps 1100.
The zero connection is blocked , Then add “ zero ”, Such as 1001,1011