Closed brackets validation

function validate(string) {
    if (string[0] == ')') {
        console.error(string + ' error: string should start with "("');
        return;
    }
    
    if (string.length % 2 !== 0) {
        console.error(string + ' error: bracket number should be even');
        return;
    }
    
    var error = false,
        length = string.length,
        open = 0;
  
    console.log(string + ', length: ' + length);
    
    for (var i = 0; i < length; i++) {
        switch (string[i]) {
            case '(':
               open++;
              
               break;
              
            case ')':
               open--;
              
               break;
        }    
        
        console.log(string[i] + ', open: ' + open);
        
        if (open < 0) {
            error = true;
            break;
        }
    }
    
    if (open !== 0) {
        error = true;
    }
    
    if (error) {
        console.error(string + ' error: string is invalid');
    } else {
        console.info(string + ' success: string is valid');
    }
}
 
var strings = [
        '((()()()))', // should be valid
        '((()()))()', // should be valid
        ')(())(',
        '()))())',
        '((()())())', // should be valid
        '((()())',
        '()))((',
        '((()())())'
    ];
 
 
for (var i in strings) {
  console.log('next array: --->');
  validate(strings[i]);   
}