How to solve "Cannot resolve symbol" in IntelliJ IDEA?

Question

I am learn Algorithms, 4th Edition with IntelliJ IDEA, however, I encouted a issue that the IDEA told me "Cannot resolve symbol 'StdIn' and 'StdOut'".

Pic: [Cannot resolve symbol "StdIn"](http: //i.imgur.com/ZRD6o53.jpg)

My project structure is correct and I set stdlib.jar as one of the dependencies, where there are StdIn and StdOut. Even I clicked "Invaildate caches and restart" the issue remains.

You may learn the details of stdlib.jar from here and Average.java

public class Average { 

   // this class should not be instantiated
   private Average() { }

    /**
     * Reads in a sequence of real numbers from standard input and prints
     * out their average to standard output.
     */
    public static void main(String[] args) { 
        int count = 0;       // number input values
        double sum = 0.0;    // sum of input values

        // read data and compute statistics
        while (!StdIn.isEmpty()) {
            double value = StdIn.readDouble();
            sum += value;
            count++;
        }

        // compute the average
        double average = sum / count;

        // print results
        StdOut.println("Average is " + average);
    }
}

If you upload a picture to a public site and edit your question to link to it, someone with more reputation can replace the link with the embedded picture. That being said, there's no reason you cannot include your code as text in your question, along with the full and exact text of the error message. — azurefrog, Apr 14 '15 at 17:37
@azurefrog I just post some links to pictures I want to upload. — hedgehog0, Apr 14 '15 at 17:57
@Makoto Yes. You can see the code from `Average.java` as I posted above. — hedgehog0, Apr 14 '15 at 17:57
**links to external resources are highly discouraged because of link rot!** — , Apr 14 '15 at 18:55

score 0 · Answer 1 · answered Apr 14 '15 at 17:53

I usually see this when I do not define a variable and try to use it, like here:

public class Animal {
    private String name;

    public String getName() {
        return name;
        address = new String(); // here I will see this error
    }

    public void setName(String name) {
        this.name = name;
    }
}

score 0 · Accepted Answer · answered Apr 14 '15 at 17:55

0

This happens because the stdlib.jar does not define package structure for its classes :(

Try creating your class on default package and that should work.

answered Apr 14 '15 at 17:55

Pavan Kumar

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How to solve "Cannot resolve symbol" in IntelliJ IDEA?

2 Answers2