Java basic series-5. Java function instances-hexadecimal conversion

Plain method: decimal --> binary

/* Decimal --> binary mod 2 returns the remainder Reverse Order */public static void Tobin (INT num) {stringbuffer sb = new stringbuffer (); While (Num> 0) {sb. append (Num % 2); num = num/2;} system. out. println (sb. reverse (); // reverse string}

Plain method: decimal --> hexadecimal

/* Decimal --> the last four digits of the binary value are converted into X/public static void tohex (INT num) {stringbuffer sb = new stringbuffer (); for (INT x = 0; x <8; X ++) // Int Is 4 8-bit, 0000-0000 0000-0000 0000-0000 0000-0000 {int temp = num & 15; // and 1111 with the operation, get the last four binary if (TEM> 9) Sb. append (char) (temp-10 + 'A'); // convert to the letter elsesb if it exceeds 9. append (temp); num = num >>> 4; // shifts 4 places to the right} system. out. println (sb. reverse ());}

Look-up method: decimal --> binary

/* Look-up table decimal --> binary */public static void Tobin (INT num) {// define the binary table char [] CHS = {'0', '1 '}; // define a temporary storage container. Char [] arr = new char [32]; int Pos = arr. length; while (num! = O) {int temp = num & 1; arr [-- POS] = CHS [temp]; num = num >>> 1 ;}for (INT x = Pos; x <arr. length; x +) {system. out. print (ARR [x]) ;}}

Look-up table method: decimal --> hexadecimal

/* Look-up table in decimal format --> hexadecimal 0 1 2 3 4 5 6 7 8 9 a B C D E F = element 0 1 2 3 4 5 6 in hexadecimal format 7 8 9 10 11 12 13 14 15 */public static void tohex (INT num) {char [] CHS = {'0', '1', '2', '3', '4', '5', '6', '7 ', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'}; // define a temporary container. Char [] arr = new char [8]; int Pos = arr. length; while (num! = 0) {int temp = num & 15; arr [-- POS] = CHS [temp]; // store num = num >>> 4;} from the last position of the array ;} for (INT x = Pos; A <arr. length; X ++) {system. out. print (ARR [x] + ',');}}

Optimize the lookup method: extract the public part

// Public static void trans (INT num, int base, int offset) {If (num = 0) {system. out. println (0); return;} Char [] CHS = {'0', '1', '2', '3', '4', '5 ', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E ', 'F'}; char [] arr = new char [32]; int Pos = arr. length; while (num! = 0) {int temp = num & base; arr [-- POS] = CHS [temp]; num = num >>> offset ;}for (INT x = Pos; x <arr. length; X ++) {system. out. print (ARR [x]) ;}/ * decimal --> binary */public static void Tobin (INT num) {TRANS (Num, 1, 1 );} /* decimal --> */public static void tooctal (INT num) {TRANS (Num, 7,3 );} /* decimal --> hexadecimal */public static void tohex (INT num) {TRANS (Num, 15,4 );}