Question

Here are snippets from my code:

class Lines{
int nameMax() throws IOException{
    // initialize variables
    // These will be the largest number of characters in name
    int namelen = 0;

    //These will be the current word lenght.     
    int namelenx = 0;

    ... 

    while(name != null){
        name = br.readLine();
        namelenx = name.length();

    ...

        if(namelenx > namelen) namelen = namelenx;


    }

    float nameleny = namelen/2; //Divides by 2 to find midpoint

    namelen = Math.round(nameleny); //Value is rounded

    return namelen;
}   
}

I am using BlueJ, and whenever I try to run this it is giving me the error in the title and highlighting namelenx = name.length(); There are String variables for name as it was part of the code I cut out. Helping answers please. Thanks.

Answer 1

It throws NPE when br.readLine() returns null, as you invoke length() on null.
your while loop should be something like below:

while((name= br.readLine())!=null){
        namelenx = name.length();

Now, even if bufferedReader returns null on readLine() your while would terminate.