Question

I have a piece of code

for(int i = 0; i < num_of_random; i++){

    String str = in.readLine();
    if(str != null){
        String[] randoms = new String[4];
        randoms = str.split(",");

        dateRanges[i] = Integer.parseInt(randoms[0]);
        id[i] = Integer.parseInt(randoms[1]);
        flag[i] = Integer.parseInt(randoms[2]);
        system[i] = Integer.parseInt(randoms[3]);
    }
}

When I run this code against findBugs, I get a suggestion for

“String[] randoms = new String[4];”

This instruction assigns a value to a local variable, but the value is not read or used in any subsequent instruction. Often, this indicates an error, because the value computed is never used.

Why do I get this?

Thanks a lot

Answer 1

Because you initialize a variable to a value (new String[4]), and then replace the variable value with another one (the result of str.split(",")) just after. The initialization is thus not necessary.

Your code is functionally equivalent to

String[] randoms = str.split(",");

except it allocates a new String array which is immediately discarded.