stack top() in C++ STL
Stacks are a type of container adaptors with LIFO(Last In First Out) type of work, where a new element is added at one end called the top of the stack, and an element is removed from the same end only.
stack::top() top() function is used to reference the top(or the newest) element of the stack.
Parameters: No value is needed to pass as the parameter.
Return Value: Direct reference to the top element of the stack container.
Input : stackname.push(5); stackname.push(1); stackname.top(); Output : 1 Input : stackname.push(5); stackname.push(1); stackname.push(2); stackname.top(); Output : 2
Errors and Exceptions
- If the stack container is empty, it causes undefined behavior
- It has a no exception throw guarantee if the stack is not empty
Given a stack of integers, find the sum of the all the integers.
Input : 1, 8, 3, 6, 2 Output: 20
- Check if the stack is empty, if not add the top element to a variable initialized as 0, and pop the top element.
- Repeat this step until the stack is empty.
- Print the final value of the variable.