将第二列和第三列从2d数组检索到数组

Question

I have a Java code that will output 3 column of double integer just like this (1 column, 2 column, 3 column):

( 0.09,  0.27,  0.01) 
( 0.00, -0.00,  0.26)  
( 0.02, -0.02,  0.24) 
( 0.22, -0.11, -0.03) 

Now, I wish to store all the values from the second column into an array and the values from the third column into another array. Is there a way I could modify it so that it will achieve that?

This is my partial code:

for (int i = 0; i < termVectors.length; ++i) {
    System.out.print("(");
    for (int k = 0; k < 3; ++k) {
    if (k > 0) System.out.print(", ");
    System.out.printf("% 5.2f",termVectors[i][k]);
    }
    System.out.print(")  ");
}

Thanks!

Answer 1

Please try the following code.

 int[] secondColVal = new int[termVectors.length];
int[] thirdColVal = new int[termVectors.length];

for (int i = 0; i < termVectors.length; ++i) {
    System.out.print("(");
    for (int k = 0; k < 3; ++k) {
    if (k > 0) System.out.print(", ");
    System.out.printf("% 5.2f",termVectors[i][k]);
    if(k==1)
    secondColVal[i] = termVectors[i][k];
    if(k==2)
    thirdColVal[i] = termVectors[i][k];
    }
    System.out.print(")  ");
}

Answer 2

This should give you what you need :)

// since you're using the length multiple times, store it in a variable!
int len = termVectors.length;
// declare two arrays to represent your second and third columns
int[] secondColumn = new int[len];
int[] thirdColumn = new int[len];

for (int i=0;i<len;i++)
{
    // populate your arrays
    secondColumn[i] = termVectors[i][1];
    thirdColumn[i] = termVectors[i][2];
}