Convert a string to a hexadecimal number saved in a int variable - string

I need a function that can convert a string containg numbers to a hexadecimal integer saved in an integer variable,
for example the function atoi(char*) converts the string in that string into a decimal number , what i need is something similar but instead of decimal , hexadecimal

All integers store data in the same format: binary. That is neither decimal or hexadecimal.
If you want to create a string from an integer, that's when you can decide if you want decimal or hexadecimal notation.
You didn't mention what language you are using so I'll just assume C or C++ from the atoi() reference. There is also an itoa() function. It will create a string from an integer, and you can specify if the string will be created using base 16, base 10, or something else.

Related

How can string be converted to number in xceptor

What enrichment/formula is required to convert a string to number in Xceptor. I tried FormatNumber
You would need to add a calculation enrichment and then use the DECIMAL([string field]) function - description for this is - DECIMAL: Converts a text string to a decimal.
You can use the INTEGER function to convert a string to an integer
For example, TestInteger = INTEGER("7600")
More information can be found here Xceptor Docs - INTEGER Function

Padding a hexadecimal string with zeros to a 6 character length

I have this:
function dec2hex(IN)
local OUT
OUT = string.format("%x",IN)
return OUT
end
and need IN to have padded zeros to string length of 6.
I can't use String.Utils or PadLeft. It's within an app called Watchmaker which uses a cut down version of Lua.
String formats in Lua work mostly just like in C. So to pad a number with zeros, just use %0n where n is the number of places. For example
print(string.format("%06x", 16^4-1))
will print 00ffff.
See chapter 20 The String Library of “Programming in Lua”, the reference of string.format, and the C reference for the printf family of functions for details.
If you store your format string locally you can call the format method on to the format string and the example of #Henri results in ("%06x"):format(0xffff)
print(("%06x"):format(0xffff)) -- Prints `00ffff`
You can write numbers in hex format. It is the same as C.

MAXIMA string to integer conversion

I am reading a list with 2 integers from a file using readline(s) which returns a string. How does one convert the string of 2 integers back to 2 integers? Thanks.
I assume you have a string like "123 456". If so you can do this: map(parse_string, split(s)) where s is your string.
parse_string parses one Maxima expression, e.g. one integer. To get both integers, split the string, which makes a list, and then parse each element of the list.

Arduino issue: String to float adds two zeros instead of the correct integer

Code snippet:
Serial.println(sensorString); //so you can see the captured string
char carray[sensorString.length() + 1]; //determine size of the array
Serial.println(sizeof(carray));
sensorString.toCharArray(carray, sizeof(carray)); //put sensorString into an array
float sensorStringFloat = atoi(carray); //convert the array into an Integer
Serial.println(sensorStringFloat);
Serial.println(sensorStringFloat) prints out 5.00 instead of the correct float value of 5.33. Why is that and how do I fix this issue? I would eventually like to pass sensorStringFloat over to:
aJson.addNumberToObject(sensor, "ph", sensorStringFloat);
atoi converts a numeral in ASCII to an integer. The comment on that line also says it converts to an integer. So you got an integer result, 5. To convert to floating-point, consider using atof. (Note that “f” stands for floating-point, not “float”. atof returns a double.)
you should pass another parameter which defines the format, in this case it is the number of digits after the floating point.
Serial.println(sensorString,2);
String temp = String (_float, 0);
say float x;
convert to String using
String _temp = String(x, 0);
The second parameter 0... says i want no trailing zeros.
Caution: However this is only suitable for whole numbers.
This solution would not work for say... 1.24
You'll get just 1.

transform string/char to uint8

Why does the expression:
test = cast(strtrim('3'), 'uint8')
produce 51?
This is also true for:
test = cast(strtrim('3'), 'int8')
Thanks.
Because 51 is the ASCII code for the character '3'.
If you want to transform the string to numeric 3, you should use
uint8(str2double('3'))
Note that str2double will ignore trailing spaces, so that strtrim isn't necessary.
EDIT
When a string is used in an numeric operation, Matlab automatically converts it to its ASCII value. For example
>> '1'+1
ans =
50
Because 51 is the ASCII value for the character '3'.
This is because '3' is seen as an ASCII character to matlab. By casting as a signed or unsigned integer (8 bits in this case) you are asking Matlab to convert an ASCII '3' to a decimal number. In this case the decimal number is 51. If you want to look at more conversions here is a basic document.

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