Android: Is there an idiom for Iterating through a SparseArray

Question

I'm using a list of unique int ids against a list of user names as a fast lookup table and decided to use the sparseArray but I would like to be able print to log the entire list from time to time for debugging purposes.

The SparseArray is not iterable and isn't much like the util.Map interface

Walkup

Similar question (with answers) can be found here – Taps

Answer 1

Mice was correct, code would look something like this;

for(int i = 0; i < sparseArray.size(); i++){
    int key = sparseArray.keyAt(i);
    Object value = sparseArray.valueAt(i);
}

Disfigure

More explanation on this solution in the comments here: https://mcmap.net/q/98665/-how-to-iterate-through-sparsearray – Benner

Answer 2

Use SparseArray.size() to get total size.

Use SparseArray.keyAt and valueAt to get key/value in given index.

Potsdam

Example with some more explanation for this solution here: https://mcmap.net/q/98665/-how-to-iterate-through-sparsearray – Benner

Answer 3

Here's how to display a SparseArray content for debug traces.

public static String sparseArrayToString(SparseArray<?> sparseArray) {
    StringBuilder result = new StringBuilder();
    if (sparseArray == null) {
        return "null";
    }

    result.append('{');
    for (int i = 0; i < sparseArray.size(); i++) {
        result.append(sparseArray.keyAt(i));
        result.append(" => ");
        if (sparseArray.valueAt(i) == null) {
            result.append("null");
        } else {
            result.append(sparseArray.valueAt(i).toString());
        }
        if(i < sparseArray.size() - 1) {
            result.append(", ");
        }
    }
    result.append('}');
    return result.toString();
}

Jehol