How to use

getIndexExpression

method

in

com.intellij.psi.PsiArrayAccessExpression

@Override
public void visitArrayAccessExpression(final PsiArrayAccessExpression expression) {
 expression.getArrayExpression().accept(this);
 myBuf.append("[");
 final PsiExpression indexExpression = expression.getIndexExpression();
 if (indexExpression != null) {
  indexExpression.accept(this);
 }
 myBuf.append("]");
}

@Nullable
private static Expression getArrayAccessExpression(@NotNull PsiArrayAccessExpression element, @NotNull Document document) {
  @Nullable PsiExpression index = element.getIndexExpression();
  AdvancedExpressionFoldingSettings settings = AdvancedExpressionFoldingSettings.getInstance();
  if (!(element.getParent() instanceof PsiAssignmentExpression
      && ((PsiAssignmentExpressionImpl) element.getParent()).getLExpression() == element) && index != null && settings.getState().isGetExpressionsCollapse()) {
    /*@Nullable Expression indexExpression = getNonSyntheticExpression(index, document);*/
    @NotNull Expression arrayExpression = getAnyExpression(element.getArrayExpression(), document);
    /*if (indexExpression instanceof NumberLiteral && ((NumberLiteral) indexExpression).getNumber().equals(0)) {
      return new ArrayGet(element, element.getTextRange(), arrayExpression, ArrayGet.Style.FIRST);
    } else */
    if (index instanceof PsiBinaryExpression) {
      PsiBinaryExpression a2b = (PsiBinaryExpression) index;
      NumberLiteral position = getSlicePosition(element, arrayExpression, a2b, document);
      if (position != null && position.getNumber().equals(-1)) {
        return new ArrayGet(element, element.getTextRange(), arrayExpression/*, ArrayGet.Style.LAST*/);
      }
    }
  }
  return null;
}

/**
 * @return true if expression can be the left part of assignment operator
 */
public static boolean isLValue(PsiExpression element) {
 if (element instanceof PsiReferenceExpression) {
  final PsiReferenceExpression expression = (PsiReferenceExpression)element;
  final PsiElement resolved = expression.resolve();
  return resolved instanceof PsiVariable;
 }
 if (element instanceof PsiParenthesizedExpression) {
  return isLValue(((PsiParenthesizedExpression)element).getExpression());
 }
 if (element instanceof PsiArrayAccessExpression) {
  final PsiArrayAccessExpression arrayAccessExpression = (PsiArrayAccessExpression)element;
  final PsiExpression arrayExpression = arrayAccessExpression.getArrayExpression();
  final PsiType type = arrayExpression.getType();
  if (type == null || !(type instanceof PsiArrayType)) return false;
  final PsiExpression indexExpression = arrayAccessExpression.getIndexExpression();
  if (indexExpression == null) return false;
  final PsiType indexType = indexExpression.getType();
  if (indexType == null) return false;
  if (getTypeRank(indexType) <= INT_RANK) return true;
 }
 return false;
}

if (variableName != null
    && initializer instanceof PsiArrayAccessExpression
    && ((PsiArrayAccessExpression) initializer).getIndexExpression() instanceof PsiReferenceExpression
    && isReferenceTo(((PsiReferenceExpression) ((PsiArrayAccessExpression) initializer).getIndexExpression()), conditionVariable)
    && conditionROperand instanceof PsiReferenceExpression
    && ((PsiReferenceExpression) conditionROperand).getQualifierExpression() instanceof PsiReferenceExpression