JS Practice — Built-in Objects

Balanced Brackets Check

📖 Usage Example

function isBalanced(s) {
  const stack = [];
  for (const c of s) {
    if (c === '(') stack.push(c);
    else if (!stack.pop()) return false;
  }
  return stack.length === 0;
}

Use a stack to verify balanced brackets by pushing opens and popping on closes.

Balanced Brackets Check

Check if a string containing brackets is balanced. Each opening bracket must have a corresponding closing bracket, and brackets must be properly nested.

Valid: "()", "()[]{}", "([{}])" Invalid: "([)]", "(()", "())"

Algorithm:

Use a stack to track opening brackets
For each character:
- If opening bracket, push to stack
- If closing bracket, check if it matches the top of stack
Stack should be empty at the end

function isBalanced(s: string): boolean {
  // Return true if brackets are balanced
}

isBalanced('([{}])') // true
isBalanced('([)]') // false

💡 Hints (5)

• Use a stack to store opening brackets.
• For each opening bracket, push it to the stack.
• For each closing bracket, check if it matches the top of the stack.
• Use an object to map closing brackets to opening brackets.
• Stack should be empty at the end.