Char to unsigned char java

Class Character

The Character class wraps a value of the primitive type char in an object. An object of class Character contains a single field whose type is char .

In addition, this class provides a large number of static methods for determining a character’s category (lowercase letter, digit, etc.) and for converting characters from uppercase to lowercase and vice versa.

Unicode Conformance

The fields and methods of class Character are defined in terms of character information from the Unicode Standard, specifically the UnicodeData file that is part of the Unicode Character Database. This file specifies properties including name and category for every assigned Unicode code point or character range. The file is available from the Unicode Consortium at http://www.unicode.org.

Character information is based on the Unicode Standard, version 15.0.

The Java platform has supported different versions of the Unicode Standard over time. Upgrades to newer versions of the Unicode Standard occurred in the following Java releases, each indicating the new version:

Variations from these base Unicode versions, such as recognized appendixes, are documented elsewhere.

Unicode Character Representations

The char data type (and therefore the value that a Character object encapsulates) are based on the original Unicode specification, which defined characters as fixed-width 16-bit entities. The Unicode Standard has since been changed to allow for characters whose representation requires more than 16 bits. The range of legal code points is now U+0000 to U+10FFFF, known as Unicode scalar value. (Refer to the definition of the U+n notation in the Unicode Standard.)

The set of characters from U+0000 to U+FFFF is sometimes referred to as the Basic Multilingual Plane (BMP). Characters whose code points are greater than U+FFFF are called supplementary characters. The Java platform uses the UTF-16 representation in char arrays and in the String and StringBuffer classes. In this representation, supplementary characters are represented as a pair of char values, the first from the high-surrogates range, (\uD800-\uDBFF), the second from the low-surrogates range (\uDC00-\uDFFF).

• The methods that only accept a char value cannot support supplementary characters. They treat char values from the surrogate ranges as undefined characters. For example, Character.isLetter(‘\uD840’) returns false , even though this specific value if followed by any low-surrogate value in a string would represent a letter.
• The methods that accept an int value support all Unicode characters, including supplementary characters. For example, Character.isLetter(0x2F81A) returns true because the code point value represents a letter (a CJK ideograph).

In the Java SE API documentation, Unicode code point is used for character values in the range between U+0000 and U+10FFFF, and Unicode code unit is used for 16-bit char values that are code units of the UTF-16 encoding. For more information on Unicode terminology, refer to the Unicode Glossary.

This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail.

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Converting char to unsigned char in Java using casting

In two’s complement systems, the leading bits represent negative numbers and this method is widely adopted. As for the solution, by default the type is assigned here. When the statement is executed, the sign bit of a certain variable is copied into the remaining bytes of another variable as. However, in the case where both variables are declared as type, the sign bit will not be copied into the remaining bytes. Therefore, the output will display the data in the variable.

Casting a char to unsigned char

Starting from C++14, char is required to be 2’s complement when signed is met.

The underlying bit pattern cannot be altered when transitioning between signed char and unsigned char casts.

0` and `(unsigned char)~0` return values of different widths?, Now we have an unsigned char with value 255, represented with bits FF. Passing that to printf results in automatic conversion to an int . Since

How to convert unsigned char* to unsigned long long int?

unsigned char test[] = "\x00\x00\x56\x4b\x7c\x8a\xc5\xde"; unsigned long long num = (unsigned long long)test[0]  

 0 0 86 75 124 138 197 222 

 94882212005342 = 0*2^56 + 0*2^48 + 86*2^40 + 75*2^32 + 124*2^24 + 138*2^16 + 197*2^8 + 222*2^0 

 long long int var = 0; memmove( &var, test, sizeof(var) ); 

#include #include int main(int argc, char *argv[]) 

public static int strtoul(byte[] bytes, int size, int base) < int total = 0; for (int i = 0; i < size; i++) < if (base == 16) < // signed bytes, shifted total += bytes[i] else < // unsigned bytes, shifted total += (bytes[i] & 0xff) > return total; > 

#include unsigned int _strtoui(char *s) < unsigned int ret; sscanf(str, "%u", &ret); /* use "%x" for hexadecimal */ return ret; >

#include uint32_t _strtoui32(char *str) < int i; uint32_t total = 0; for(i=0; str[i] != '\0'; i++) total = total*10 + str[i] - '0'; return total; >uint32_t _hextoui32(char *str) < int i; uint32_t total = 0; for(i=0; str[i] != '\0'; i++) < total *= 16; if(str[i] >47 && str[i] < 58) /* base 10 number */ total += str[i] - '0'; else if(str[i] >64 && str[i] < 71) /* uppercase A-F */ total += str[i] - 'A' + 10; else /* lowercase a-f */ total += str[i] - 'a' + 10; >return total; > uint32_t _hstrtoui32(char *str, int base) 

c1 => 1000 0110 | signed bit is set(1)