Find arthimatic operator in string by Using Regex

 function ArthimaticOperation(val) {
        //var str="45/52";
        var patt1=/[-|*|/|+]{1}/g;
        var operator=val.match(patt1);
        var temp = new Array();
        temp = val.split(val.match(patt1));
        var firstVal=temp[0];
        var secVal=temp[1];
        if(operator=='*')
            return firstVal*secVal;
        else if(operator=='-')
            return firstVal-secVal;
        else if(operator=='+')
            return firstVal+secVal;
        else if(operator=='/')
            return firstVal/secVal;
        else
            return val;

    }