numbers interview questions
Top numbers frequently asked interview questions
What's the "best" way to convert a number to a string (in terms of speed advantage, clarity advantage, memory advantage, etc) ?
Some examples:
String(n)
n.toString()
""+n
n+""
Source: (StackOverflow)
In Haskell, what is the difference between an Int
and an Integer
? Where is the answer documented?
Source: (StackOverflow)
I need to loop some values,
for i in $(seq $first $last)
do
does something here
done
For $first
and $last
, i need it to be of fixed length 5. So if the input is 1
, i need to add zeros in front such that it becomes 00001
. It loops till 99999
for example, but the length has to be 5.
E.g.: 00002
, 00042
, 00212
, 012312
and so forth.
Any idea on how i can do that?
Source: (StackOverflow)
For input type="number" element, maxlength is not working. How can I restrict the maxlength for that number element?
Source: (StackOverflow)
I have a string in javascript like `#box2' and I just want the '2' from it.
Tried:
var thestring = $(this).attr('href');
var thenum = thestring.replace( /(^.+)(\w\d+\w)(.+$)/i,'$2');
alert(thenum);
It still returns #box2 in the alert, how can I get it to work?
It needs to accommodate for any length number attached on the end.
Source: (StackOverflow)
I need to format a float to "n"decimal places.
was trying to BigDecimal, but the return value is not correct...
public static float Redondear(float pNumero, int pCantidadDecimales) {
// the function is call with the values Redondear(625.3f, 2)
BigDecimal value = new BigDecimal(pNumero);
value = value.setScale(pCantidadDecimales, RoundingMode.HALF_EVEN); // here the value is correct (625.30)
return value.floatValue(); // but here the values is 625.3
}
I need to return a float value with the number of decimal places that I specify.
I need "Float" value return not "Double".
Thanks in advance.
Source: (StackOverflow)
What's the correct way to round a PHP string to 2 decimal places?
$number = "520"; // It's a string from a DB
$formatted_number = round_to_2dp($number);
echo $formatted_number;
Output is "520.00";
What's round_to_2dp
look like?
Source: (StackOverflow)
Trying to get the highest and lowest value from a array that I know will contain only integers seems to be harder than I thought?
var numArray = [140000, 104, 99];
numArray = numArray.sort();
alert(numArray[0] + ", " + numArray[numArray.length - 1]);
I'd expect this to show "99, 140000". Instead it shows "104, 99". So it seems the sort is handling the values as strings?
Any way to get the sort function to actually sort on integer value?
Source: (StackOverflow)
PHP - Is there a quick, on-the-fly method to test for a single character string, then prepend a leading zero?
Example:
$year = 11;
$month = 4;
$stamp = $year.add_single_zero_if_needed($month); // Imaginary function
echo $stamp; // 1104
Source: (StackOverflow)
I am looking for an easy way in JavaScript to check if a number has a decimal place in it (is an integer). For instance,
23 -> OK
5 -> OK
3.5 -> not OK
34.345 -> not OK
if(number is integer) {...}
Source: (StackOverflow)
This is weird. This is what happens at the JavaScript console in Chrome (version 42.0.2311.135, 64-bit).
> 0
< 0
> 00
< 0
> 0.0
< 0
> 00.0
X Uncaught > SyntaxError: Unexpected number
Firefox 37.0.2 does the same, although its error message is:
SyntaxError: missing ; before statement
There's probably some technical explanation regarding the way JavaScript parses numbers, and perhaps it can only happen when tinkering at the console prompt, but it still seems wrong.
Why does it do that?
Source: (StackOverflow)
What is the simplest most basic way to find out if a number/variable is odd or even in PHP?
Is it something to do with mod?
I've tried a few scripts but.. google isn't delivering at the moment.
Source: (StackOverflow)
Is it possible to get a random number between 1-100 and keep the results mainly within the 40-60 range? I mean, it will go out of that range rarely, but I want it to be mainly within that range... Is it possible with JavaScript/jQuery?
Right now I'm just using the basic Math.random() * 100 + 1
.
Source: (StackOverflow)
I would extract all the numbers contained in a string. Which is the better suited for the purpose, regular expressions or the isdigit()
method?
Example:
line = "hello 12 hi 89"
Result:
[12, 89]
Source: (StackOverflow)
Django has various numeric fields available for use in models, e.g. DecimalField and PositiveIntegerField. Although the former can be restricted to the number of decimal places stored and the overall number of characters stored, is there any way to restrict it to storing only numbers within a certain range, e.g. 0.0-5.0 ?
Failing that, is there any way to restrict a PositiveIntegerField to only store, for instance, numbers up to 50?
Update: now that Bug 6845 has been closed, this StackOverflow question may be moot. - sampablokuper
Source: (StackOverflow)