CODEWITHSUNDEEP
javascript
Joel DeWitt
Joel DeWitt

Reputation: 1306

Working with 2-D arrays in JS

I know that multi-dimensional arrays are not natively supported in JS, but I would like to shoehorn them in a calculation I'm doing. For example, I have:

amn1 = new Array(4);
for (j = 0; j < amn1.length; j = j + 1) {
  amn1[j] = new Array(4);
}
amn1[0][0] = -8.72500;
amn1[0][1] = 1.88000;
amn1[0][2] = 0.741900;
amn1[0][3] = 0.752000;
amn1[1][0] = 0.83090;
amn1[1][1] = 0.11140;
amn1[1][2] = -0.528800;
amn1[1][3] = -0.555890;
amn1[2][0] = -0.13396;
amn1[2][1] = -0.06481;
amn1[2][2] = 0.126423;
amn1[2][3] = 0.128431;
amn1[3][0] = 0.01262;
amn1[3][1] = 0.00540;
amn1[3][2] = -0.009341;
amn1[3][3] = -0.009306;
for (u = 0; u < 4; u = u + 1) {
  for (n = 0; n < 4; n = n + 1) {
    amn1[u][n] = amn1[u][n] * logt + amn1[u][n];
  }
  loglambda = loglambda + amn1[u][n];
  loglambda = loglambda * logi;
}

Assume my script is linted and all variables are properly declared and initialized. Now, checking to see if JS understands the contents of amn1 in the inner loop, it does. However, in the outer loop a check of the console output reveals undefined. Keeping the logic the same, this works in a procedural language, but not here (I have a working version of this in Fortran).

Why does this not work?

Upvotes: 2

Views: 73

Answers (1)

Eugene P.
Eugene P.

Reputation: 2625

dead simple : 

loglambda = loglambda + amn1[u][n];

on that line your N will always be 4.

Keeping in mind the size of your array : you have only j = [0,1,2,3] for each amn1[i][j].

Upvotes: 3

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