Check if an expression is balanced or not. Return the index. if not balanced

Balanced-Expressions.js

const checkBalancedExpr = (expr) => {
    let stack = [];

    for(let i = 0; i < expr.length; i++) {
        let char = expr[i];

        const brackets = ['(', ')', '[', ']', '{', '}']
        if(!brackets.includes(char)) {
            continue;
        }

        if (char === '(' || char === '[' || char === '{') {
            stack.push(char);
            continue;
        }

        if (stack.length === 0) {
            return [false, i];
        }

        let check = stack.pop();
        switch (char) {
            case ')':
                if (check !== '(') {
                    return [false, i];
                }
                break;
            case '}':
                if (check !== '{') {
                    return [false, i];
                }
                break;
            case ']':
                if (check !== '[') {
                    return [false, i];
                }
                break;
            }
    }

    if (stack.length === 0) {
        return true;
    }
    return [false, stack.length - 1];
}