Java face question

0. Write a function to find out where the keyword ' _ ' in the string appears all the places (such as ' _ ' in "Acd124_145po_c" where the position is 6 and 12)

1  Packagecn.union;2 3 Importjava.util.ArrayList;4 Importjava.util.List;5 6  Public classUnion4 {7 8      Public Static voidMain (string[] args) {9         //TODO auto-generated Method StubTen  OneString str = "Acd124_145po_c"; A  - System.out.println (Find_ (str)); -     } the  -     Private StaticList<integer>find_ (String str) { -         //TODO auto-generated Method Stub -  +list<integer> result =NewArraylist<integer> ();//List Storage Results -         Char[] Chararr = Str.tochararray ();//converting a string to a character array +  A          for(inti = 0; i < chararr.length; i++) { at             if(' _ ' = =Chararr[i]) { -Result.add (i);//If you have _, add to the list -             } -         } -  -         returnresult; in     } -}

1. Write a function to find the second largest element in the shape array a (with only one layer of loops)

1  Packagecn.union;2 3  Public classUnion5 {4 5      Public Static voidMain (string[] args) {6         //TODO auto-generated Method Stub7 8         int[] A = {10, 1, 9, 2, 8, 3, 7, 4, 6, 5 };9 Ten System.out.println (Findsecondmax (a)); One     } A  -     Private Static intFindsecondmax (int[] a) { -         //TODO auto-generated Method Stub the  -         if(NULL= = A | | A.length <= 1) { -             return-1; -         } +  -         intmax = a[0] > a[1]? A[0]: a[1]; +         intSecondmax = a[0] + a[1]-Max; A  at          for(inti = 2; i < a.length; i++) { -             if(A[i] >max) { -Secondmax =Max; -Max =A[i]; -}Else if(A[i] >Secondmax) { -Secondmax =A[i]; in             } -         } to  +         returnSecondmax; -     } the}

2. Run the above program, the output is:

-128

Because the maximum byte value is 127, the minimum value is-128

1  Packagecn.union;2 3  Public classTest {4 5      Public Static voidMain (string[] args) {6         //TODO auto-generated Method Stub7 8         bytei =Byte.max_value;9         bytej = + +i;Ten System.out.println (j); One     } A}

3. Write a method to flip a string (such as the string "abcdef" to "FEDCBA")

1  Packagecn.union;2 3  Public classUnion7 {4 5      Public Static voidMain (string[] args) {6         //TODO auto-generated Method Stub7 8String str = "ABCdef";9 Ten System.out.println (Myreverse (str)); One     } A  -     Private Staticstring Myreverse (String str) { -         //TODO auto-generated Method Stub the  -         Char[] Charstr =Str.tochararray (); -         Char[] result =New Char[charstr.length]; -         intFlag = 0; +  -          for(inti = charstr.length-1; I >= 0; i--) { +Result[flag] =Charstr[i]; Aflag++; at         } -  -         returnstring.valueof (result); -     } -}

Java face question