2.8 KiB
2.8 KiB
id | title | challengeType |
---|---|---|
587d8250367417b2b2512c5e | Learn how a Stack Works | 1 |
Description
push()
method that pushes JavaScript objects at the top of the stack; and pop()
method, that removes the JavaScript object that's at the top of the stack at the current moment.
Instructions
"BIO12"
is at the base, and "PSY44"
is at the top of the stack.
Modify the given array and treat it like a stack
using the JavaScript methods mentioned above. Remove the top element "PSY44"
from the stack. Then add "CS50"
to be the new top element of the stack.
Tests
tests:
- text: <code>homeworkStack</code> should only contain 4 elements.
testString: assert(homeworkStack.length === 4, '<code>homeworkStack</code> should only contain 4 elements.');
- text: The last element in <code>homeworkStack</code> should be <code>"CS50"</code>.
testString: assert(homeworkStack[3] === 'CS50', 'The last element in <code>homeworkStack</code> should be <code>"CS50"</code>.');
- text: <code>homeworkStack</code> should not contain <code>"PSY44"</code>.
testString: assert(homeworkStack.indexOf('PSY44') === -1, '<code>homeworkStack</code> should not contain <code>"PSY44"</code>.');
- text: The initial declaration of the <code>homeworkStack</code> should not be changed.
testString: assert(code.match(/=/g).length === 1 && /homeworkStack\s*=\s*\["BIO12"\s*,\s*"HIS80"\s*,\s*"MAT122"\s*,\s*"PSY44"\]/.test(code), 'The initial declaration of the <code>homeworkStack</code> should not be changed.');
Challenge Seed
var homeworkStack = ["BIO12","HIS80","MAT122","PSY44"];
// Only change code below this line
Solution
// solution required