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stack.js
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stack.js
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class Stack {
// Array is used to implement stack
constructor(max_size)
{
this.items = [];
this.max_size = max_size;
}
// push an element into stack
push(element)
{
// push element into the list items
if(this.size() < this.max_size)
this.items.push(element);
else return "overflow";
}
// pop an element from the stack
pop()
{
if (this.items.length == 0)
return "underflow";
return this.items.pop();
}
// Check if the stack is empty
isEmpty()
{
// return true if stack is empty
return this.items.length == 0;
}
// Return the top most element of the stack / Most recently added element.
peek()
{
return this.items[this.items.length - 1];
}
// return the number of elements in the stack
size(){
return this.items.length;
}
}
module.exports = Stack