Octals and Hexadecimals

JavaScript FAQ | JavaScript Numbers FAQ  

Question: Is there a way to use octal and hexadecimal numbers in JavaScript?

Answer: Yes, in JavaScript you can use octals and hexadecimals.

The following are examples of octal numbers:
01234 -077 0312
Positive octal numbers must begin with 0 (zero) followed by octal digit(s).
Negative octal numbers must begin with -0 followed by octal digit(s).

And these are examples of hexadecimal numbers:
0xFF -0xCCFF 0xabcdef
Positive hexadecimals must begin with 0x and negative hexadecimals must begin with -0x.

When you need to convert an octal or hexadecimal string to a number, use the function parseInt(str,base). Consider these examples:

num = parseInt(octalStr,8);  // num now holds 255

num = parseInt(hexStr,16);   // num now holds 127
The second argument of parseInt specifies the base of the number whose representation is contained in the original string. This argument can be any integer from 2 to 36.

See also:

  • Converting numbers to another base
  • Mathematical functions in JavaScript
  • Random numbers in JavaScript
  • Rounding in JavaScript
  • Accuracy of JavaScript arithmetic
  • Can I display mathematical symbols as part of JavaScript output?
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