C++ string length [duplicate] - c++

This question already has answers here:
What does the C++ standard state the size of int, long type to be?
(24 answers)
Getting the actual length of a UTF-8 encoded std::string?
(11 answers)
Closed 2 years ago.
I was reading the documentation of string::length and, as you can see, it says that
Returns the length of the string, in terms of bytes.
So my question is, is this ensured to be also the number of char that it contains?
I know that usually a char is 1 byte, but is this ensured somewhere? Like in the standard or somewhere else?

Related

Input of integer in the range of 10^1000 [duplicate]

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Handling large numbers in C++?
(10 answers)
Closed 8 years ago.
Is it possible to take an input of range greater than what C/C++ provides? Is it possible to accept an input range greater than that of unsigned long long and even larger up to the range of 10^1000?
If it is possible in C/C++, please answer how it can be done, thanks.
There's no bigint in C or C++, however library like this one can provide it: https://code.google.com/p/infint/
Input into a string. Then convert the string into the desired type.
If you use a library that provides types for large integers, such a library might also offer input functions.

What is the difference between 0x and '\x' in C++? [duplicate]

This question already has answers here:
What does \x mean in C/C++?
(7 answers)
strlen - the length of the string is sometimes increased by 1
(1 answer)
Closed 8 years ago.
I know that hex-decimal number is usually prefixed with 0x in C/C++ language.
For example, 0x5A means 90 in decimal.
But I saw an example code using single-quoted character with '\x'.
BYTE outputBuffer[index++] = '\x5A'; // instead of 0x5A
Is the meaning of '\x5A' exactly the same as 0x5A?
If so, why is there alternative way of hex-decimal notation?
For a character, both are quite equal.
But only one can be mixed into a string with other normal characters. "ABC\x5A"
And only one can be used to initialize a large integral type: long long x = 0x1234567812345678LL;

How does C++ understand two letter characters [duplicate]

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Multicharacter literal in C and C++
(6 answers)
What do single quotes do in C++ when used on multiple characters?
(5 answers)
Closed 9 years ago.
C++ seems to allow up to four characters to be held in single quotes, such as:
char c = 'abcd';
but at runtime, only the last value ('d') seems to be actually stored away. This behavior seems to happen for pairs of two, three, or four (at five the compiler finally calls uncle). But what's the deal with this design? I don't really see the logic in it.

boolean operator in c++ [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
What does 'unsigned temp:3' mean?
I saw some c++ code today that used single colons.
bool variable_name : 1;
what is the difference between this and
bool variable_name = true;
The ": 1" means it is a bit field with 1 bit, or at least that's what it means in C. It probably was put there to save some memory, allowing multiple bools to be stored in the same byte. The downside is that you probably can't make a pointer to that bool.

How many characters does string class in c++ support? [duplicate]

This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
Maximum length of a std::basic_string<_CharT> string
I would like to know how many characters does string class in c++ support.
thanks..
std::string s;
s.max_size();
That should tell you what that max size is.
according to http://www.idinews.com/string3.html
The std::string class supports varying length strings with no length limit.
I am lead to believe that the size of a std::string object is limited to size of an unsigned integer on the architecture of your system. I would assume this since the length of the string is stored as a size_t value.