octal

Converting Decimal to Hexadecimal and Octal

由 自作多情 提交于 2019-12-11 06:16:32
问题 Show how to write a constant in C, whose decimal value is 65 as a. a hexadecimal constant 65/16 = 1 r1 1/16 = 0 r1 Hexadecimal constant = 11 b. an octal constant (in C) 65/8 = 8 r1 8/8 = 1 r0 1/8 = 0 r1 Octal constant = 101 Is this the right way to convert constants in C? 回答1: You just need a while loop and a string. As this is homework, I do not think I should say more than that. 回答2: The method is to divide by the base until the result is less than the base. So 65/8 gives 8 r1 but you don't

How to prevent PHP from doing octal math in conditionals? (why does 08 === 0)

由 一世执手 提交于 2019-12-11 06:14:45
问题 I was working with code that parses crontab. https://stackoverflow.com/a/5727346/3774582 I found it works great, however I found that if I made a cron like 0 * * * * It would run at the 0 minute, the 8th minute, and the 9th minute. I broke down every line of the code. https://gist.github.com/goosehub/7deff7928be04ec99b4292be10b4b7b0 I found that I was getting this conditional for the value of 0 if the current minute was 8. 08 === 0 I tested this with PHP if (08 === 0) { echo 'marco'; } After

Linux terminal octal form of chmod

由 前提是你 提交于 2019-12-11 05:47:53
问题 I want to set a directory to -rwx r-x r-x using the octal form of chmod what should i type in the terminal after chmod? and how do i calculate the digits in octal form? 回答1: It goes like this: rwx rwx rwx 421 421 421 so what you want is rwx r-x r-x 421 4-1 4-1 7 5 5 so you type chmod 755 nameofdirectory 来源： https://stackoverflow.com/questions/19085653/linux-terminal-octal-form-of-chmod

what is the reason for the difference between setprecision (12) and setprecision (012) for example,in c++?

由 a 夏天 提交于 2019-12-10 23:03:15
问题 In c++ when you write setprecision (12) for example, 12 is in the base of 10 but when you write it like setprecision (012) it is an octal number,why? 回答1: Because constants with leading zeros (other than leading 0x) are always octal: An octal integer literal (base eight) begins with the digit 0 and consists of a sequence of octal digits. C++ draft standard (n1905) §2.13.1 It has nothing at all to do with setprecision. 回答2: Because that's how it worked in C. Back when C was designed, octal

Are “unit-relevant” CSS property values with prepended zeroes equivalent to the corresponding “no-zeroes-prepended” values?

由 耗尽温柔 提交于 2019-12-10 16:23:56
问题 I was scanning some stylesheets when I noticed one which used a linear-gradient with rgba() color-stops in which the rgba numbers used multiple instances of 0 instead of just a single 0 : background-image:linear-gradient(to top left, rgba(000,000,000,0.1),rgba(100,100,100,1)); I hadn't seen multiple zeroes (instead of a single zero) occupying a single slot in the rgb/a color space before, but confirmed on CodePen this is valid. I then looked up the W3C definition of number here. To make a

Why is 032 different than 32 in Ruby?

由 偶尔善良 提交于 2019-12-09 01:42:41
问题 I have noticed Ruby behaves differently when working with 032 and 32. I once got syntax errors for having 032 instead of just 32 in my code. Can someone explain this to me? Or is there something really wrong with my code itself? 回答1: What you're seeing is 032 is an octal representation, and 32 is decimal: >> 032 #=> 26 >> 32 #=> 32 >> "32".to_i(8) #=> 26 >> "32".to_i(10) #=> 32 And, just for completeness, you might need to deal with hexadecimal: >> 0x32 #=> 50 >> "32".to_i(16) #=> 50 and

Where did the octal/hex notations come from? [closed]

由 醉酒当歌 提交于 2019-12-08 23:42:33
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 6 years ago . After all of this time, I've never thought to ask this question; I understand this came from c++, but what was the reasoning behind it: Specify decimal numbers as you normally would Specify octal numbers by a leading 0 Specify hexadecimal numbers by a leading 0x Why 0? Why 0x? Is there a natural progression for

Why would you write in Octal/Hexadecimal/Binary over Standard Notation?

由 一曲冷凌霜 提交于 2019-12-08 02:50:17
问题 I was reading the PHP documentation on Integers, where it's specifies the different ways in which you can specify which notation to use. Here's a snippet of the doc for anyone interested. <?php $a = 1234; // decimal number $a = -123; // a negative number $a = 0123; // octal number (equivalent to 83 decimal) $a = 0x1A; // hexadecimal number (equivalent to 26 decimal) $a = 0b11111111; // binary number (equivalent to 255 decimal) ?> However, in PHP (and even some other programming languages

How to convert an input of 3 octal numbers into CHMOD permissions into Binary?

由 旧时模样 提交于 2019-12-07 06:08:36
I am trying to create a program that takes input from the user using the command line of 3 octal number, for example 5, 2, 6 or 5,2,6 and convert them into 3 sets of 3 digit binary numbers, like 101 010 110, and also print out those corresponding CHMOD permissions like r-x -w- rw-. I am having a lot of trouble splicing these numbers apart with substring into 3 separate numbers of 5 2 and 6. I also need the program to convert from the set of binary digits into 3 numerical digits and permissions. And from the permissions into digits and binary. Here is what I have so far: import java.util

Why would you write in Octal/Hexadecimal/Binary over Standard Notation?

由 折月煮酒 提交于 2019-12-06 11:42:11
I was reading the PHP documentation on Integers , where it's specifies the different ways in which you can specify which notation to use. Here's a snippet of the doc for anyone interested. <?php $a = 1234; // decimal number $a = -123; // a negative number $a = 0123; // octal number (equivalent to 83 decimal) $a = 0x1A; // hexadecimal number (equivalent to 26 decimal) $a = 0b11111111; // binary number (equivalent to 255 decimal) ?> However, in PHP (and even some other programming languages where applicable), why would you ever choose to write in Octal, Hexadecimal, or Binary notation over
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