Sum rows in javascript (not a table)
I have an textarea for input of values that are rows and columns (but not a table) and I want to be able to add the values of the rows individually. My logic is that I get the user to input the number of rows they have entered, split the input to make a string and then split it up by the number of rows they input. Hereis what I have. Happy for better solutions. Alternately I did some reading and thought I could convert the rows to actual <tr>s and then go through them (I would also like to be able to this for columns at a later stage). Thanks in advance:
<html>
<head>
<script type='text/javascript'>
function sum(){
var rows= document.getElementById('rows').value;
var val = document.getElementById('userInput').value;
var temp = val.split(" ");
var lines=temp.split(rows);
var total = 0;
var v;
for(var i = 0; i < temp.length; i++) {
v = parseFloat(lines[i]);
//this is what I am missing to get each row's sum separately
}
document.write(//each row total);
}
</script>
</head>
<body>
<form id="input">
<textarea id="userInput"></textarea>
Number of rows: <textarea id="rows"></textarea>
<input id="Run" type=Button value="run" onClick="sum()" />
</form>
</body>
</html>
So now I have the following (I had to add v back in) but it is returning NaN (and noting I will address the final suggestion anyway):
<script type='text/javascript'>
function sum() {
var grandTotal = 0,
rowTotals = [], // array to hold individual row totals
rowData,
rows,
val,
var v;
rawData = document.getElementById('userInput').value;
rows = rawData.split("\n");
for (var i=0; i < rows.length; i++) {
rowTotals[i] = 0;
rowData = rows[i].split(" ");
for (var j=0; j < rowData.length; j++) {
val = parseFloat(rowData[j]);
if (!isNa开发者_如何学PythonN(v)) rowTotals[i] += v;
}
alert("Total for row " + (i + 1) + ": " + rowTotals[i]);
grandTotal += rowTotals[i];
}
alert("Grand total: " + grandTotal);
}
</script>
Assuming the user has entered data in this format:
12.1 4.8 11.2 4.1
1.2 3.4 5.6 99.9
etc
That is, with a new line at the end of each row and spaces between the numbers, then you could do something like this:
function sum() {
var grandTotal = 0,
rowTotals = [], // array to hold individual row totals
rowData,
rows,
val,
rawData = document.getElementById('userInput').value;
// if desired replace this comment with regex validation of rawData
rows = rawData.split("\n");
for (var i=0; i < rows.length; i++) {
rowTotals[i] = 0;
rowData = rows[i].split(" ");
// if you need to test that each row has the same number
// of values in it do that here
for (var j=0; j < rowData.length; j++) {
val = parseFloat(rowData[j]);
// add validation of val here
rowTotals[i] += val;
}
alert("Total for row " + (i + 1) + ": " + rowTotals[i]);
grandTotal += rowTotals[i];
}
// at this point rowTotals is an array containing
// the individual row totals, so do what you like with that
alert("Grand total: " + grandTotal);
}
There are two points in the function where you will need to do some more work:
- You must check that the result from
parseFloat()is actually a number - the user may have entered alphabetic characters or punctuation, in which case it'll returnNaN. Alternatively use a regular expression to validate the whole string for formatting and illegal characters before you do anything else. - Splitting the string on newline "\n" can be a problem in that different platforms use different characters for line breaks. I believe some use just newline "\n", some use just carriage return "\r" and some use both. You could probably normalise that before the split using a find-and-replace.
I leave both points as an exercise for the reader...
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