Re: Integer Check

if (isNan(myVariable)) {
alert('incorrect, not a number');
} else {
if ((myVariable % 1)!=0) {
alert('Number can not be a floating-point');
} else return true;

return false;
}

Vincent van Beveren wrote:

if (isNan(myVariable)) {
alert('incorrect, not a number');
} else {
if ((myVariable % 1)!=0) {
alert('Number can not be a floating-point');
} else return true;

return false;
}

Why not:
function isInteger(num){
return (!isNaN(num) && num%1==0);
}
?
Mick

Mick White wrote on 20 apr 2004 in comp.lang.javascript:

Vincent van Beveren wrote:

if (isNan(myVariable)) {
alert('incorrect, not a number');
} else {
if ((myVariable % 1)!=0) {
alert('Number can not be a floating-point');
} else return true;

return false;
}



Why not:
function isInteger(num){
return (!isNaN(num) && num%1==0);
}
?
Mick

return !(isNaN(num) || !(num % 1));

or

return !isNaN(num) && !!(num % 1);


--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

Why not:
function isInteger(num){
return (!isNaN(num) && num%1==0);
}
?
Mick



return !(isNaN(num) || !(num % 1));

or

return !isNaN(num) && !!(num % 1);

I just wrote the code as a draft. Any of these are good.

return (!isNaN(num)) && ((num % 1)==0)

would probably be the most relayable... since num % 1 is a
calculation, it would be better to see if it matches a number,
even though 0 == false.

Vincent van Beveren wrote on 21 apr 2004 in comp.lang.javascript:

return !(isNaN(num) || !(num % 1));

or

return !isNaN(num) && !!(num % 1);


I just wrote the code as a draft. Any of these are good.

return (!isNaN(num)) && ((num % 1)==0)

would probably be the most relayable... since num % 1 is a
calculation, it would be better to see if it matches a number,
even though 0 == false.

I do not know about this relaying,
but any nonzero number is considered true in javascriot.

var nonzeronumber = 2;
alert(!!nonzeronumber) // gives true

var zeronumber = 0;
alert(!!zeronumber) // gives false

--
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

Evertjan. wrote:

Vincent van Beveren wrote on 21 apr 2004 in comp.lang.javascript:
return !(isNaN(num) || !(num % 1));

or

return !isNaN(num) && !!(num % 1);


I just wrote the code as a draft. Any of these are good.

return (!isNaN(num)) && ((num % 1)==0)

would probably be the most relayable... since num % 1 is a
calculation, it would be better to see if it matches a number,
even though 0 == false.

I do not know about this relaying,
but any nonzero number is considered true in javascriot.

var nonzeronumber = 2;
alert(!!nonzeronumber) // gives true

var zeronumber = 0;
alert(!!zeronumber) // gives false

If there is a desire to explicitly return a boolean value, but avoid the
extra comparisons, it might be practical to apply the NOT operator to
the result of the whole expression:-

return !(isNaN(num)||(num % 1));

Richard.