If number ends with 1 do something

Question

I want to make something like this:

if(day==1 || day==11 || day==21 || day==31 || day==41 ......){
    result="dan";
}
else{
    result="dana";
}

How can i do that with every number that ends with one and of course without writing all numbers?

I removed mentions of jQuery which is a library for manipulating the DOM, not doing math. — JJJ, Dec 06 '13 at 20:54
You could also turn the number into a string and use the slice() method to check the last value. Not sure which would be more performant, but it likely doesn't matter. — ernie, Dec 06 '13 at 22:19
@Juhana Yeah right, not gonna fall with that, jQurery doesn't know math... Dude jQuery is math! — gdoron, Dec 10 '13 at 23:54

Shad · Accepted Answer · 2013-12-06T21:21:13.757

60

Just check the remainder of division by 10:

if (day % 10 == 1) { 
  result = "dan";
} else {
  result = "dana";
}

% is the "Modulo" or "Modulus" Operator, unless you're using JavaScript, in which case it is a simple remainder operator (not a true modulo). It divides the two numbers, and returns the remainder.

edited Dec 06 '13 at 21:21

answered Dec 06 '13 at 20:53

Shad

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score 17 · Answer 2 · edited May 23 '17 at 12:31

You can check the remainder of a division by 10 using the Modulus operator.

if (day % 10 == 1)
{ 
   result = "dan";
}
else
{
   result = "dana";
}

Or if you want to avoid a normal if:

result = "dan" + (day % 10 == 1 ? "" : "a");

% is the Javascript Modulus operator. It gives you the remainder of a division:

Example:

11 / 10 = 1 with remainder 1.
21 / 10 = 2 with remainder 1.
31 / 10 = 3 with remainder 1.
...

See this answer: What does % do in JavaScript? for a detailed explication of what the operator does.

score 7 · Answer 3 · answered Dec 06 '13 at 20:54

7

Modulus operator. You can research it but basically you want to detect if a number when divided by 10 has a remainder of 1:

if( day%10 == 1)

answered Dec 06 '13 at 20:54

AaronLS

37,329
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score 1 · Answer 4 · edited Oct 23 '14 at 20:21

1

this can be solved by single line

return (day % 10 == 1) ? 'dan' : 'dana';

edited Oct 23 '14 at 20:21

ROMANIA_engineer

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answered Oct 23 '14 at 19:58

Manivannan

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agm1984 · Answer 5 · 2022-01-25T21:41:35.767

You can convert the number to a string and use String.prototype.endsWith().

const number = 151

const isMatch = number.toString().endsWith('1')

let result = ''

if (isMatch) {
    result = 'dan'
} else {
    result = 'dana'
}

I'm using it in some code that sets the ordinal. For example, if you want to display 1st, 2nd, 3rd, or 4th:

        let ordinal = 'th';
        if (number.toString().endsWith('1')) {
            ordinal = 'st'
        }
        if (number.toString().endsWith('2')) {
            ordinal = 'nd'
        }
        if (number.toString().endsWith('3')) {
            ordinal = 'rd'
        }

If number ends with 1 do something

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