Question

To preface this, we are a small organization and this system was built by someone long ago. I am a total novice at javascript so I have trouble doing complicated things, but I will do my best to understand your answers. But unfortunately redoing everything from scratch is not really an option at this point.

We have a system of collecting data where clients use a login to verify a member ID, which the system then uses to pull records from an MS Access database to .ASP/html forms so clients can update their data. One of these pages has the following function that runs on form submit to check that data in fields a/b/c sum to the same total as d/e/f/g/h/i. It does this separately for each column displayed (each column is a record in the database, each a/b/c/d/e/f is a field in the record.)

The problem is with this section of the function:

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for (var j=0; j<recCnt; j++) {
   sumByType = milesSurf[j] + milesElev[j] + milesUnder[j];
   sumByTrack = milesSingle[j] + milesDouble[j] + milesTriple[j] + milesQuad[j] + milesPent[j] + milesSex[j];

etc.

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It should use javascript FOR to loop through each record and test to see if they sum to the same thing.

In Firefox and IE this is working properly; the fields sum properly into “sumByType” and “sumByTrack”. You can see below I added a little alert to figure out what was going wrong:

alert(sumByType + " " + j + " " + recCnt + " " + milesSurf[j] + " " + milesElev[j] + " " + milesUnder[j]);

In Chrome, that alert tells me that the components of “sumByType” and “sumByTrack” (the various “milesXXXXX” variables) are undefined.

My question is: Why in Chrome is this not working properly, when in IE and FFox it is? Any ideas?

Full function code below:

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function submitCheck(formy, recCnt) {
//2/10/03: added milesQuad
//---------------checks Q#4 that Line Mileage by type is the same as by track     
var milesElev = new Array(); 
var milesSurf = new Array();
var milesUnder = new Array(); 
var milesSingle = new Array();
var milesDouble = new Array(); 
var milesTriple = new Array();
var milesQuad = new Array();
var milesPent = new Array();
var milesSex = new Array();
var sumByType = 0;
var milesLineTrack = new Array();   //this is for Q5 to compare it to mileage by trackage
var j = 0; var sumByTrack = 0; var liney; var yrOp;
//var str = "document.frm.milesElev" + j;
//alert(str.value);
for (var i in document.frm) {
    if (i.substring(0, i.length - 1) == "milesElev") {
        milesElev[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }   
    if (i.substring(0, i.length - 1) == "milesSurf") {
        milesSurf[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }
    if (i.substring(0, i.length - 1) == "milesUnder") {
        milesUnder[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }
    if (i.substring(0, i.length - 1) == "milesSingle") {
        milesSingle[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }
    if (i.substring(0, i.length - 1) == "milesDouble") {
        milesDouble[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }
    if (i.substring(0, i.length - 1) == "milesTriple") {
        milesTriple[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }
    if (i.substring(0, i.length - 1) == "milesQuad") {
        milesQuad[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }
    if (i.substring(0, i.length - 1) == "milesPent") {
        milesPent[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }
    if (i.substring(0, i.length - 1) == "milesSex") {
        milesSex[parseInt(i.substring(i.length-1, i.length))] = parseFloat(document.frm[i].value); }
    if (i.substring(0, i.length -1) == "milesLineTrack") {
        milesLineTrack[parseInt(i.substring(i.length-1, i.length))] = document.frm[i].value; }  //12/13/02 used to be parseFloat(document.frm[i].value)
    if (i.substring(0,5)=="Lines") {
        liney = document.frm[i].value;
    if (parseInt(liney)<1 || isNaN(liney)) {
        alert("Each mode must have at least 1 line.  Please correct the value in question #2."); 
        document.frm[i].select(); return false; }}
    if (i.substring(0,8)=="yearOpen") { 
        yrOp = document.frm[i].value;
        if (parseInt(yrOp)<1825 || isNaN(yrOp)) {
            alert("Please enter a year after 1825 for question #3"); 
            document.frm[i].select(); return false; }
    }
}
for (var j=0; j<recCnt; j++) {
    sumByType = milesSurf[j] + milesElev[j] + milesUnder[j];
    sumByTrack = milesSingle[j] + milesDouble[j] + milesTriple[j] + milesQuad[j] + milesPent[j] + milesSex[j];

    //---------------to round sumByTrack and sumByType from a long decimal to a single decimal place, like frm 7.89999998 to 7.9.
    sumByTrack = sumByTrack * 10;
    if (sumByTrack != parseInt(sumByTrack)) {
        if (sumByTrack - parseInt(sumByTrack) >= .5) {
        //round up
            sumByTrack = parseInt(sumByTrack) + 1; }
        else {  //truncate
            sumByTrack = parseInt(sumByTrack); }}
    sumByTrack = sumByTrack / 10;
    sumByType = sumByType * 10;
    if (sumByType != parseInt(sumByType)) { 
        if (sumByType - parseInt(sumByType) >= .5) {
        //round up
            sumByType = parseInt(sumByType) + 1; }
        else {  //truncate
            sumByType = parseInt(sumByType); }}
    sumByType = sumByType / 10;
    //-------------end of rounding ---------------------------

    if (sumByType != sumByTrack) {
        if (isNaN(sumByType)) { 
            sumByType = "(sum of 4.a., b., and c.) "; }
        else {
            sumByType = "of " + sumByType; }
        if (isNaN(sumByTrack)) { 
            sumByTrack = "(sum of 4.d., e., f., g., h., and i.) "; }
        else {
            sumByTrack = "of " + sumByTrack; }
        alert("For #4, the 'End-to-End Mileage By Type' " + sumByType + " must equal the 'End-to-end Mileage By Trackage' " + sumByTrack + ".");
        alert(sumByType + " " + j + " " + recCnt + " " + milesSurf[j] + " " + milesElev[j] + " " + milesUnder[j]);
        return false;
    }
    //alert (milesLineTrack[j] + "  " + milesSingle[j] + "  " + 2*milesDouble[j] + "  " + 3*milesTriple[j] + "  " + 4*milesQuad[j] + "  " + 5*milesPent[j] + "  " + 6*milesSex[j]);
    var singDoubTrip = (milesSingle[j] + 2*milesDouble[j] + 3*milesTriple[j] + 4*milesQuad[j] + 5*milesPent[j] + 6*milesSex[j])
    //----------round singDoubTrip to one digit after the decimal point (like from 6.000000001 to 6.0)
    singDoubTrip = singDoubTrip * 10;
    if (singDoubTrip != parseInt(singDoubTrip)) { 
        if (singDoubTrip - parseInt(singDoubTrip) >= .5) {
        //round up
            singDoubTrip = parseInt(singDoubTrip) + 1; }
        else {  //truncate
            singDoubTrip = parseInt(singDoubTrip); }}
    singDoubTrip = singDoubTrip / 10;
    //----------end round singDoubTrip-----------------------------------------
    if (parseFloat(milesLineTrack[j]) != singDoubTrip) {
        //var mlt = milesLineTrack[j];
        //if isNaN(milesLineTrack[j]) { mlt = 
        alert("For column #" + (j+1) + ", the mainline passenger track mileage of " + milesLineTrack[j] + " must equal the single track plus 2 times the double track plus 3 times the triple track plus 4 times the quadruple track plus 5 times the quintuple track plus 6 times the sextuple track, which is " + singDoubTrip + ".");
        return false; 
    }
}
//---------------------end of checking Q#4----------------

//return false;

}

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Answer 1

I think for (var i in document.frm) is the problem. You should not enumerate a form element, there will be plenty of unexpected properties – see Why is using "for…in" with array iteration a bad idea?, which is especially true for array-like objects. I can’t believe this works properly in FF 🙂

Use this:

var ele = document.frm.elements; // or even better document.getElementById("frm")
for (var i=0; i<ele.length; i++) {
    // use ele[i] to access the element,
    // and ele[i].name instead of i where you need the name
}

Also, you should favour a loop over those gazillion of if-statements.