Balancing string

function isValid(s) {
const stack = [];
const map = { ')': '(', ']': '[', '}': '{' };

for (let char of s) {
    if (char in map) { // If it's a closing bracket
        if (stack.pop() !== map[char]) return false; // Check last open bracket
    } else {
        stack.push(char); // Push opening brackets
    }
}

return stack.length === 0;

}

console.log(isValid("{[()]}")); // true
console.log(isValid("{[(])}")); // false
console.log(isValid("{[()")); // false