Java Utililty Methods Stack Usage

int index = decl.length() - 1;
Stack<Character> stack = new Stack<Character>();
for (int i = 0; i < token.length(); index--) {
    if (decl.charAt(index) == ' ' || decl.charAt(index) == '\t')
        continue;
    char c = decl.charAt(index);
    stack.push(c);
    i++;
...

Stack<Integer> binaryStack = new Stack<Integer>();
while (input != 0) {
    binaryStack.push((int) input % 2);
    input = input / 2;
return binaryStack;

String[] operands = new String[nOperands];
for (int j = nOperands - 1; j >= 0; j--) {
    if (stack.isEmpty()) {
        String msg = "Too few arguments supplied to operation. Expected (%d) operands but got (%d)!";
        msg = String.format(msg, nOperands, nOperands - j - 1);
        throw new IllegalStateException(msg);
    operands[j] = stack.pop();
...

if (order[order.length - 1] != 0) {
    permutations.add(order.clone());
for (Stack<Byte> stack : remaining) {
    if (stack.empty()) {
    } else {
        order[index] = stack.pop();
        getPermutationsRec(permutations, order, remaining, index + 1);
...

List<String> result = new ArrayList<>();
Stack<String> stack = new Stack<>();
for (int i = 0; i < inOrderList.size(); i++) {
    if (Character.isDigit(inOrderList.get(i).charAt(0))) {
        result.add(inOrderList.get(i));
    } else {
        switch (inOrderList.get(i).charAt(0)) {
        case '(':
...

StringBuilder sb = new StringBuilder();
sb.append('/');
int size = pathStack.size();
for (int i = 0; i < size; i++) {
    sb.append(pathStack.get(i)).append('/');
return sb.toString();

List syllables = new ArrayList();
Stack last = new Stack();
Stack next = new Stack();
for (int i = pinyin.length() - 1; i >= 0; i--) {
    next.push(new Character(pinyin.charAt(i)));
do {
    char c = ((Character) next.pop()).charValue();
...

if (!bufStack.isEmpty() && bufStack.peek() == '"') {
    return true;
return false;

if (curDir == null) {
    return null;
StringBuffer buf = new StringBuffer(curDir);
int maxIndex = buf.length();
int thisIndex = buf.indexOf("/");
Stack<Integer> slashStack = new Stack<Integer>();
while ((thisIndex != -1) && (thisIndex != maxIndex)) {
...

if (cont == null)
    return null;
int len = cont.length();
Stack<Character> stack = new Stack<Character>();
char c;
for (int i = 0; i < len; i++) {
    c = cont.charAt(i);
    if (c == ')') {
...