The sum() method will calculate the numeric sum of array values. Array values that are not numeric are treated as if they were zeros.
Return Value
Sum as a numeric value.
Example
pjs.define("Num", { type: 'integer', length: 10, dim: 5 });
Num[1] = 1;
Num[2] = 2;
Num[3] = 3;
Num[4] = 4;
Num[5] = 5;
return Num.sum();
//15