isValidParentheses created by wwebby1 - https://repl.it/EcdZ/1

isValidParentheses.js

function validParentheses(parens){
	
	if(parens[0] == ")")
	return false;
  if(parens[parens.length-1] == "(")
  return false;
	for(var i = 0; i < parens.length-1; i++)
	{
		if(parens[i]=="(" && parens.length%2 == 0)
		{
			for(var k = i+1; k < parens.length; k++)
			{
				if(parens[k] == ")")
				return true;
			}
			
		}
	}
return false;
}
console.log(validParentheses( "()" ) );
console.log(validParentheses( ")(()))" ));
console.log(validParentheses( "(" ));
console.log(validParentheses( "(())((()())())" ));