Java: Embedded Equals Statements in While Loop

Question

I was wondering if someone could explain to me what the line of code below does?

while((sample = samples.read()) != null)

Does it first set sample equal to the next line of samples, and then check to make sure it's not empty?

This is more a general question, but if anyone has a good tutorial for OpenNLP, I would really appreciate that, as well.

Here is the method in its entirety:

public static Dictionary buildNGramDictionary(ObjectStream samples, int cutoff) throws IOException {

    NGramModel ngramModel = new NGramModel();
    POSSample sample;

    while((sample = samples.read()) != null) {
        String[] words = sample.getSentence();
        if (words.length > 0)
            ngramModel.add(new StringList(words), 1, 1);
    }

    ngramModel.cutoff(cutoff, Integer.MAX_VALUE);
    return ngramModel.toDictionary(true);
}

Answer 1

The evaluation of the expression is dictated by operator precedence.
The expression inside the brackets (sample = samples.read()) is evaluated first because the () brackets have a higher precedence than the !=