function checkSyntax(str) {
	var arr = [];
	var open = '({<[';
	var close = ')}>]'

	for (var i = 0; i <= str.length; i++) {
		var x = open.indexOf(str[i]);
		var y = close.indexOf(str[i]);
		if (x >= 0) {
			arr.push(str[i]);
		}
		if ((y >= 0) && (arr[arr.length-1] == open[y]))  {
			arr.pop();
		}

	}
	return (arr.length == 0) ? 0 : 1;
}
console.log(checkSyntax("({<})"));
console.log(checkSyntax("") );
console.log(checkSyntax("before ( middle []) after ") );
console.log(checkSyntax(") (") );
console.log(checkSyntax("} {") );
console.log(checkSyntax("<(   >)") );
console.log(checkSyntax("(  [  <>  ()  ]  <>  )") );
console.log(checkSyntax("   (      [)") );