Loop through array and return sum of all values
What I want to do is have numbers inputted by user and the sum of the numbers returned. My logic is as follows:
- User inputs string
- String is split to array
- Loop through array and sum all numbers
- Return sum
And here is the code I have so far:
<script type='text/javascript'>
var val=document.getElementById('userInput').value;
var temp=val.split(" ");
function sum() {
for(var i=0, MISSING THIS BIT
document.getElementById('resultSum').innerHTML=MISSING THIS BIT;
}
</script>
<form name="input">
<textarea name="userInput" rows=20 cols=20></textarea>
<input name="Run" type=Button value="run" onClick="sum()">
<form name="resultSum"><input type=Text>
I admit with humility that this is mostly probably wrong and appreciate anybody's time and effort.
UPDATE: I have done as suggested and I get the following error on my code below:
Message: 'document.getElementById(...)' is null or not an object Line: 16 Char: 1 Code: 0
<html>
<script type='text/javascript'>
function sum(){
var val = document.getElementById('userInput').value;
var temp = val.split(" ");
var total = 0;
var v;
for(var i = 0; i < temp.length; i++) {
v = parse开发者_Go百科Float(temp[i]);
if (!isNaN(v)) total += v;
}
document.getElementById('resultSum').innerHTML=total;
}
</script>
<form name="input">
<textarea name="userInput" rows=20 cols=20></textarea>
<input name="Run" type=Button value="run" onClick="sum()">
<form name="resultSum"><input type=text>
<html>
Any suggestions? Thanks to all for being comprehensive - I have read both examples and understand the process now!
You want a basic loop to convert and add each item.
I have also cleaned up your HTML a ton. You didn't have any proper closing tags. I have also changed all of the 'name' attributes to 'id' attributes so that 'getElementById' would work properly, which I missed on my first pass.
<html>
<head>
<script type='text/javascript'>
function sum(){
var val = document.getElementById('userInput').value;
var temp = val.split(" ");
var total = 0;
var v;
for(var i = 0; i < temp.length; i++) {
v = parseFloat(temp[i]);
if (!isNaN(v)) total += v;
}
document.getElementById('resultSumValue').value = total;
}
</script>
</head>
<body>
<form id="input">
<textarea id="userInput" rows=20 cols=20></textarea>
<input id="Run" type=Button value="run" onClick="sum()" />
</form>
<form id="resultSum">
<input id="resultSumValue" type="text" />
</form>
</body>
</html>
This will also ignore any values that are 'NaN' (Not a Number).
If you want the numbers to only be integers (no decimals), change parseFloat to parseInt.
Here is an outline, but I think it's worth writing it yourself to learn.
- split() returns an array of characters. You can get the length of that array with temp.length
- You'll want to loop over every element of that array.
- Because "1" + "2" = "12" in javascript, you need to convert your characters to integers
- Keep a running total of the sums, and add to it at each iteration of the loop, maybe validating that each number is a real number
First start by declaring a variable set to 0 before the for loop. Iterate over each element in the array (array.length) adding to the variable you set before the for loop.
<html>
<head>
<title>sum input</title>
<style>
p, textarea,input{font-size:24px}
textarea,input{text-align:right}
</style>
<script>
function sum(){
var val= document.getElementById('userInput').value.replace(/^\D+|D+$/g,'');
document.getElementById('resultSum').value= eval(val.replace(/\D+/g,'+'));
}
</script>
</head>
<body>
<p>Enter a series of numbers :<br>
<textarea id="userInput" rows="10" cols="10"></textarea><br>
<input id="Run" type="button" value="Sum" onClick="sum()">
<input id="resultSum" type="text" readOnly>
</p>
</body>
</html>
加载中,请稍侯......
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