Updated to allow full whole numbers and then a fraction

fracToDeci.js

function toDeci(fraction) {
    var result,wholeNum=0, frac, deci=0;
    if(fraction.search('/') >=0){
        if(fraction.search('-') > 0){
            var wholeNum = fraction.split('-');
            frac = wholeNum[1];
            wholeNum = parseInt(wholeNum,10);
        }else if(fraction.search(' ') > 0){
			var wholeNum = fraction.split(' ');
	        fraction = wholeNum[1];
	        wholeNum = parseInt(wholeNum,10);        
        } else{
            frac = fraction;
        }
        if(fraction.search('/') >=0){
            frac = fraction.split('/');
            deci = parseInt(frac[0], 10) / parseInt(frac[1], 10);
        }
        result = wholeNum+deci;
    }else{
        result = fraction
    }
    return result;
}
 
console.log('1 ',toDeci("1-7/16"));
console.log('2 ',toDeci("5/8"));
console.log('3 ',toDeci("3-3/16"));
console.log('4 ',toDeci("12 1/4"));
console.log('5 ',toDeci("12.2"));