Java, Printing the stack values

问题

In Java, I want to print the contents of a Stack. The toString() method prints them encased in square brackets delimited by commas: [foo, bar, baz].

The question is, how do I get rid of them and print the variables only?

My code so far:

Stack myStack = new Stack ();
for(int j=0;j<arrayForVar.length;j++) {
if(arrayForVar[j][1]!=null) {
  System.out.printf("%s \n",arrayForVar[j][1]+"\n");
  myStack.push(arrayForVar[j][1]);
}
System.out.printf("%s \n",myStack.toString());

This answer worked for me:

Use the toString method on the Stack, and use replaceAll method to replace all instances of square brackets with blankstring. Like this:

System.out.print(
    myStack.toString().replaceAll("\\[", "").replaceAll("]", ""));

回答1:

There is a workaround.

You could convert it to an array and then print that out with Arrays.toString(Object[]):

System.out.println(Arrays.toString(myStack.toArray()));

回答2:

Use the same kind of loop that you used to fill the stack and print individual elements to your liking. There is no way to change the behavior of toString, except if you go the route of subclassing Stack, which I wouldn't recommend. If the source code of Stack is under your control, then just fix the implementation of toString there.

回答3:

Use toArray() to print the stack values

public void printStack(Stack<Integer> stack) {

        // method 1:
        String values = Arrays.toString(stack.toArray());
        System.out.println(values);

        // method 2:
        Object[] vals = stack.toArray();
        for (Object obj : vals) {
            System.out.println(obj);
        }
    }

回答4:

stack.forEach(System.out::println);

Using Java 8 and later stream functions

回答5:

From documentation of toString() method of AbstractCollection. So you can not do it unless you define your own StackOr implement custom toString() by iterating over Stack

public String toString()

Returns a string representation of this collection. The string representation consists of a list of the collection's elements in the order they are returned by its iterator, enclosed in square brackets ("[]"). Adjacent elements are separated by the characters ", " (comma and space). Elements are converted to strings as by String.valueOf(Object).

This implementation creates an empty string buffer, appends a left square bracket, and iterates over the collection appending the string representation of each element in turn. After appending each element except the last, the string ", " is appended. Finally a right bracket is appended. A string is obtained from the string buffer, and returned.

回答6:

Throwing a suggestion into the pool here. Depending on your Stack implementation this may or may not be possible.

The suggestion is an anonymous inner class for overriding the toString() in this particular case. This is one way to locally implement the subclassing Marko is mentioning. Your Stack instantiation would look something like

Stack s = new Stack(){
              public String toString(){
                 // query the elements of the stack, build a string and
                 return nicelyFormattedString;
              }
          };
...

回答7:

Try this:

 System.out.println(Arrays.asList(stackobject.toArray()));
 System.out.println(Arrays.toString(stackobject.toArray()));

来源：https://stackoverflow.com/questions/12160183/java-printing-the-stack-values

标签

java

stack