打印字符从2d数组java

Question

如何从2D数组中打印字符，逐列而不是逐行?另外，如何让字符填充数组呢?我知道你必须使用for循环但是我一直得到的字符串是逐行读取的。

String command = args[0]; 
    String Text = args[1]; //leters to be 
    char letters [] = Text.toCharArray(); 
    int m = Text.length(); //number of letters to be decrypted/encrypted

    if (command.equals("-encrypt")) {
        if ( m / (int) Math.sqrt(m) == Math.sqrt(m) ) { //if m is a perfect square no. eg.4,9,16
            int RootM = (int) Math.sqrt(m); //find depth and width of grid, square therfore depth = width
            char [][] box = new char [RootM][RootM]; //define and create grid 
        for (int i=0; i<RootM; i++) {
            for (int j=0; j<RootM; j++) {
                box[i] = letters; //change this to read each column
                System.out.print(Text); //displays encrypted text
            }
        }
     }
        else if     ( m / (int) Math.sqrt(m) != Math.sqrt(m) ) { //non perfect square digits
        int RootM = (int) Math.pow((Math.sqrt(m))+1,2); //overall size of 2d array (depth*width)
        int RootN1 = (int) Math.sqrt(RootM); //length of rows & columns
        char [][] box = new char [RootN1][RootN1]; //define dimensions of 2d array
            for (int i=0; i<RootN1; i++) {
                for (int j=0; j<RootN1; j++) {
                    box[j] = letters; //change this to read each column
            System.out.println(Text); //displays encrypted text

Answer 1

char [][] box = new char [5][3];//5 rows, 3 columns
for(int i =0;i<3; i++){
    for (int j = 0; j < 5; j++) {//Iterate rows
        System.out.println(box[j][i]);//Print colmns
    }   
}