Array issue when the length is below 5 - javascript

Listing last five items in an array by using this code below worked so far, but when the array length was only 1 it started causing issues. Can I some how condition it so it doesn't cycle though when there is only one item in the array?
$(function() {
$.getJSON("#myURL", function(getStressTestErrorInfo2) {
if (getStressTestErrorInfo2.length >= 1) {
var len = getStressTestErrorInfo2.length - 5;
var data = getStressTestErrorInfo2;
var txt = "";
if (data.length - 1 !== undefined) {
for (var i = len; i < len + 5; i++) {
// dynamically generating a table-row for appending in the table.
txt += "<tr><td>" + data[i].AlarmNo + "</td><td>" + data[i].AlarmCnt + "</td><td>" + data[i].StresstestId + "</td><td>" + data[i].StresstestRunId + "</td><td>" + data[i].Name + "</td><td>" + data[i].StackTrace + "</td><td>" + data[i].Timestamp + "</td></tr>";
}
if (txt != "") {
// #table is the selector for the table element in the html
$("#listErrorsTest2").append(txt);
}
}
};
});
});

Change this line:
if (getStressTestErrorInfo2.length >= 1) {
to:
if (getStressTestErrorInfo2.length >= 5) {
This way, it wont start the function, if the length is lower then 5.

The issues you have is that no matter the size of the array, you take the size and substract 5 to it. Allowing you to take the last 5 cells of an array ... long enough. If the length is below 5, the index will be negative.
Now, you can't simply update the condition if you want to get the values of smaller arrays.
You can simply set the index to 0 if it is negative :
var len = getStressTestErrorInfo2.length - 5;
if (len < 0) len = 0; //Array with less than 5 values.
And loop until you reach the end
while(len < getStressTestErrorInfo2.length){ ... }

My approach at the begging had some (stupid) flaws. Instead of showing the last 5 items I reversed the array and listed first five and added the condition
if (len > 5) len = 5;
so it did the trick.
$(function() {
$.getJSON("#myURL", function(getStressTestErrorInfo0) {
if (getStressTestErrorInfo0.length >= 1) {
var data = getStressTestErrorInfo0;
/*Function to reverse the array*/
function reverseArr(input) {
var ret = new Array;
for (var i = input.length - 1; i >= 0; i--) {
ret.push(input[i]);
}
return ret;
}
var reverseData = reverseArr(data);
var len = getStressTestErrorInfo0.length;
var data = getStressTestErrorInfo0;
var txt = "";
if (len > 0) {
if (len > 5) len = 5;
for (var i = 0; i < len; i++) {
// dynamically generating a table-row for appending in the table.
txt += "<tr><td>" + reverseData[i].AlarmNo + "</td><td>" + reverseData[i].AlarmCnt + "</td><td>" + reverseData[i].StresstestId + "</td><td>" + reverseData[i].StresstestRunId + "</td><td>" + reverseData[i].Name + "</td><td>" + reverseData[i].StackTrace + "</td><td>" + reverseData[i].Timestamp + "</td></tr>";
}
if (txt != "") {
//selector for the table element in the html
$("#listErrors").append(txt);
}
}
};
});
});

Related

Assigning instances to my array (javascript). Whats causing this error?

I need to assign instances of my object as values in my array, but when I try to add let to my loop for collecting user input, I get an error stating that "[" is an unexpected token. This is a new technique to me so I'm not sure if this is even a practical method for making a table. Any help is appreciated.
<script>
function generateTable() {
var tblStart = "<table>";
//This is the header line for my table.
var tblMeat = "<tr> <td><b>Name</b></td> <td><b>Attendance</b></td> <td><b>Homework</b></td> <td><b>Midterm</b></td> <td><b>Final</b></td> <td><b>Course Grade</b></td> <td><b>Round Grade</b></td> <td><b>Letter Grade</b></td> </tr>";
var tblStop = "</table>";
//This determines the number of rows.
var rowCount = prompt("How many students are in the class?");
//I want to assign instances of Student to this array which will be used to fill the table cells.
var pupil = [NUMBER(rowCount)];
//This object should process user entries and use them to calculate the total grade, rounded grade, and letter grade.
function Student(name, attendance, homework, mGrade, fGrade) {
this.name = name;
this.attend = attendance;
this.homewrk = homework;
this.midter = mGrade;
this.fingrad = fGrade;
this.course = function () {
var attGrade = this.attend * 0.1;
var hwkGrade = this.homewrk * 0.2;
var midGrade = this.midter * 0.3;
var finGrade = this.fingrad * 0.4;
var combGrade = attGrade + hwkGrade + midGrade + finGrade;
return combGrade.toFixed(2);
};
this.round = Math.round(this.course);
this.letter = function() {
if(this.course < 60) {
return '<p style="color:red;">F</p>';
} else if(this.course >= 60 && this.course <= 69.9){
return "D";
} else if(this.course >= 70 && this.course <= 79.9) {
return "C";
} else if(this.course >= 80 && this.course <= 89.9) {
return "B";
} else if(this.course >= 90 && this.course <= 100) {
return "A";
};
};
}
/*This loop should collect user input based on the declared number of students, and assign input values to instances of
Student based on which execution of the loop is being run. I am getting an error stating "[" is unexpected for line 79.
*/
for (var r = 0; r < rowCount; r++) {
var studentN = prompt("Enter student name.");
var studentA = prompt("Enter student attendance.");
var studentH = prompt("Enter student homework grade.");
var studentM = prompt("Enter student midterm grade.");
var studentF = prompt("Enter student final grade.");
let pupil[r] = new Student(studentN, studentA, studentH, studentM, studentF);
}
for(var i = 0; i < rowCount; i++) {
tblMeat += "<tr>";
for(var j = 0; j < 8; j++) {
tblMeat += "<td>" + pupil[i].name + "</td><td>" + pupil[i].attend + "</td><td>" + pupil[i].homewrk + "</td><td>" + pupil[i].midter + "</td><td>" + pupil[i].fingrad + "</td><td>" + pupil[i].course() + "</td><td>" + pupil[i].round + "</td><td>" + pupil[i].letter() + "</td>";
}
tblMeat += "</tr>";
}
//This just puts it all together.
var completeTable = tblStart + tblMeat + tblStop;
document.getElementById("placetable").innerHTML = completeTable;
}
</script>
I ran your program through uglifyJS. It's actually for compressing javascript code, but when there is a lot of code to debug, it's a life changer.
The script told me:
Parse error: Unexpected token: punc ([)
Line 59, column 16
let pupil[r] = new Student(studentN, studentA, studentH, studentM, studentF);
You're trying to define an already existing variable. Remove "let".
A tiny advice for the future.

After calling function I'm getting error saying undefined

In my table 1st column has a tags with href's and 3rd column has some text. So, I want to save all href's into an array where their respective 3rd column matches some string and use it for later purpose. I had tried the following code nothing seems wrong to me, can some one assist me with this.
function findimagelinks(){
var rows = jQuery(".sortable tr.even").length + jQuery(".sortable tr.odd").length;
var imglinks = [];
for (i=0; i<rows; i++){
var conditionvalue =jQuery(".sortable tr:eq(i+1) td:eq(3)").text();
if(conditionvalue == "some string"){
imglinks[i] = jQuery(".sortable tr:eq(i+1) td:eq(0) a").attr('href');
}
}
console.log(imglinks);
}
findimagelinks();
String concatenation is not right!
var conditionvalue = jQuery(".sortable tr:eq(" + (i + 1) + ") td:eq(3)").text();
// ------------------------------------------^
imglinks[i] = jQuery(".sortable tr:eq(" + (i + 1) + ") td:eq(0) a").attr('href');
// -----------------------------------^
Updated Snippet
function findimagelinks(){
var rows = jQuery(".sortable tr.even").length + jQuery(".sortable tr.odd").length;
var imglinks = [];
for (i = 0; i < rows; i++) {
var conditionvalue = jQuery(".sortable tr:eq(" + (i + 1) + ") td:eq(3)").text();
if (conditionvalue == "some string") {
imglinks[i] = jQuery(".sortable tr:eq(" + (i + 1) + ") td:eq(0) a").attr('href');
}
}
console.log(imglinks);
}
findimagelinks();
Your selector is wrong. Properly concatenate the strings like this
var conditionvalue = jQuery(".sortable tr:eq(" + (i + 1) + ") td:eq(3)").text();
Then your code will look like,
for (i = 0; i < rows; i++) {
var conditionvalue = jQuery(".sortable tr:eq(" + (i + 1) + ") td:eq(3)").text();
if (conditionvalue == "some string") {
imglinks[i] = jQuery(".sortable tr:eq(" + (i + 1) + ") td:eq(0) a").attr('href');
}
}

Javascript event not defined in Firefox

This has been asked before but I'm still struggling to wrap my head around how to fix the error in my case. I'm new to learning Javascript/jQuery. Firefox gives an error "ReferenceError: getFirstArr is not defined". I have a simplified script of what I'm trying to do here JSFiddle (to make it work, select a year button first before a month button).
The culprit seems to be the getFirstArr(videos[i]) line 28. I really don't even know what to try since my code seems correct. It works in Safari, Chrome and IE. Firefox is the odd man out. Here's a snippet of the on click event where the problem is.
$('.campbutton').on('click', function () {
camp = $(this).attr('id');
$('.campbutton').removeClass('green');
$(this).addClass('green');
$('#searcharea').html('<table></table>');
var campyear = camp + year;
var count = 1;
var noResultCount = 0;
for (i = 0; i < videos.length; i++) {
for (j = 0; j < 5; j++) {
getFirstArr(videos[i]); // Firefox doesn't like this line
function getFirstArr(video) { // prints the the array where a match is found
The JSFiddle will have the whole code. So my question is, why is Firefox not accepting the function call, and what needs to be changed? Any help or hints are appreciated (btw, I'm still working on getting the correct table tags to format the output correctly so the videos don't just stack on top of themselves).
Edit: The specific problem Firefox has is when the camp button is clicked, no videos load in the div. The other button events are fine.
Here's the entire code in question:
var videos = [ ["string1A", "string1B", "string1C"], ["string2A", "String2B", String2C"] ];
var camp = "";
var year = "";
$('#searcharea').html('select a year button first');
$('.yearbutton').on('click', function () {
year = $(this).attr('id');
$('.yearbutton').removeClass('green');
$(this).addClass('green');
});
$('.campbutton').on('click', function () {
camp = $(this).attr('id');
$('.campbutton').removeClass('green');
$(this).addClass('green');
$('#searcharea').html('<table></table>');
var campyear = camp + year;
var count = 1;
var noResultCount = 0;
for (i = 0; i < videos.length; i++) {
for (j = 0; j < 5; j++) {
getFirstArr(videos[i]);
function getFirstArr(video) {
if (campyear === video[j]) {
var pos = video.indexOf(video[j]);
$('#searcharea').append('<tr><td>' + video[(pos - pos)] + '</td>' + '<td>' + 'Composer: ' + video[(pos -pos) + 1] + '<br>' + 'Player: ' + video[(pos - pos) + 2] + '<br>' + 'Piece: ' + video[(pos - pos) + 3] + '</td>');
}
else noResultCount++;
if (campyear === video[j] && count % 3 === 0 && j === 4)
$('#searcharea').append('</tr><tr>');
if (i === videos.lenght && j === 4)
$('#searcharea').append('</table>');
}
}
count++;
}
if (noResultCount === videos.length * 5)
$('#searcharea').html("No results found");
});
http://jsfiddle.net/3ncc5xdx/123/
Here i have moved your function to outside the loop like so, I think it works, unless I misunderstood what the issue is:
$('.campbutton').on('click', function () {
camp = $(this).attr('id');
$('.campbutton').removeClass('green');
$(this).addClass('green');
$('#searcharea').html('<table></table>');
var campyear = camp + year;
var count = 1;
var noResultCount = 0;
function getFirstArr(video) {
if (campyear === video[j]) {
var pos = video.indexOf(video[j]);
$('#searcharea').append('<tr><td>' + video[(pos - pos)] + '</td>' + '<td>' + 'Composer: ' + video[(pos -pos) + 1] + '<br>' + 'Player: ' + video[(pos - pos) + 2] + '<br>' + 'Piece: ' + video[(pos - pos) + 3] + '</td>');
}
else noResultCount++;
if (campyear === video[j] && count % 3 === 0 && j === 4)
$('#searcharea').append('</tr><tr>');
if (i === videos.lenght && j === 4)
$('#searcharea').append('</table>');
}
for (i = 0; i < videos.length; i++) {
for (j = 0; j < 5; j++) {
getFirstArr(videos[i]);
}
count++;
}
if (noResultCount === videos.length * 5)
$('#searcharea').html("No results found");
});
So the reason that it works is that the function is now declared before it is used once. Also, its now only declared once rather than again and again in your loop. It probably works in Chrome because Chrome is pretty smart and figuring our what you were implying – but Firefox will need a slightly more strict approach.

Compare month in nested object array

The following problem is causing me some headache. I'm building an application to compare transaction data with a list of tenants and what they're supposed to pay for rent.
I've got it running nicely except it compares EACH transaction with the monthly rent. What I want to do is first add all (relevant) transaction amounts per month and then compare them.
Should I just build another nested for-loop to compare all the transaction months before I run this loop? I could potentially drop in years of transaction data making it quite inefficient...
Any tips are greatly appreciated.
var table = "<table><thead><tr><th>Rek</th><th>Name</th><th>Date</th><th>Amount</th><th>Rent</th><th>Diff</th></tr></thead><tbody>";
for (var i = 0; i < data.length; i++) {
for (var j = 0; j < tenant.length; j++) {
if (tenant[j].reks.indexOf(data[i].rek) == -1)
continue;
else {
var diff = tenant[j].rent - data[i].amount; //TODO monthly!!!
var style = " style='background-color: ";
if (diff > 0)
style += "red;'";
else
style += "green;'";
table += "<tr><td>" + data[i].rek
+ "</td><td>" + data[i].name
+ "</td><td>" + (data[i].date.getMonth() + 1) + "-" + data[i].date.getFullYear()
+ "</td><td>€ " + data[i].amount
+ "</td><td>€ " + tenant[j].rent
+ "</td><td" + style
+ ">" + diff
+ "</td></tr>";
}
}
}
table += "</tbody></table>";
$('#top').html(table);

Javascript function - works in IE, not in chrome

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:
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.
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:
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;
}
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.

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