CODEWITHSUNDEEP
javascript
user460920
user460920

Reputation: 887

conversion of hexa to decimal int

In javascript how the hexadecimal and octal integers are converted to the decimal values:

For example:

var num=parseInt("0x10");
 document.write(num);

It displays as output the value 16 how??

Upvotes: 0

Views: 1164

Answers (3)

Linus Thiel
Linus Thiel

Reputation: 39261

Javascript's parseInt takes an optional second argument radix, specifying which base you want to convert to. From MDN parseInt:

If radix is undefined or 0, JavaScript assumes the following:

If the input string begins with "0x" or "0X", radix is 16 (hexadecimal).

If the input string begins with "0", radix is eight (octal).

This feature is non-standard, and some implementations deliberately do not support it (instead using the radix 10). For this reason always specify a radix when using parseInt.

If the input string begins with any other value, the radix is 10 (decimal).

In your case, specifying the radix 10

var num = parseInt("0x10", 10)

yields num == 0, while radix 16

var num = parseInt("0x10", 16)

yields num == 16 (since 0x10 when interpreted as a hexadecimal number equals 16 in decimal (base 10).

It is always good to specify the radix you expect to interpret your input in.

Upvotes: 1

Lightness Races in Orbit
Lightness Races in Orbit

Reputation: 385385

the hexadecimal and octal integers are converted to the decimal values

No.

No, no, no.

When you do parseInt (passing the base parameter please!), the number represented in the string input is converted to binary for internal representation, and by default outputting a number does so in decimal.

The number, as stored, is neither "decimal" or "octal" at all.

If you want the hexadecimal representation, then print it as such:

var num=parseInt("0x10", 16);
document.write(number.toString(16));

Upvotes: 1

Sunil Kumar B M
Sunil Kumar B M

Reputation: 2795

var hexnum = parseInt("0x10", "16"); //for hexadecimal
var octnum = parseInt("10", "8");  //for octal

Upvotes: 1

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