Common methods in the String class

There are many methods and construction methods in the String class: First, Common construction methods: 1, public string () string Str=new string ("ABCDEFG") 2, public string (byte[] bytes): By byte number      The group constructs a string object byte[]b={' A ', ' B ', ' C ', ' d '};      String T1=new string (b); SYSTEM.OUT.PRINTLN (t1); Output: ABCD 3, Public String (byte[] bytes,int offset, int length): bytes-the byte,offset to decode as a character-the index of the first byte to decode, length-to decode       The number of bytes byte[]b={' A ', ' B ', ' C ', ' d '};       String T3=new string (b,1,2);   System.out.println (T3);       Output: BC 4, public string (char[] value): Constructs a String object through a char array char[]c={' 0 ', ' 1 ', ' 2 ', ' 3 '};       String T4=new string (c);   System.out.println (T4); Output: 0123 5, public String (char[] value,int offset,int count): value-as an array of word mnemonic, offset-initial offset, count-length char[]c={' 0 '       , ' 1 ', ' 2 ', ' 3 '};       String T5=new string (c,1,3); System.out.println (T5); Output: 1232, Common Method: String Object string Str= "ABCDEFG" string str1= "BCDEFG" as example 1, public char charAt (int index): return refers to The char value at the fixed index.         The index range is from 0 to length ()-1.  Char Str2=str.charat (2);     System.out.println (STR2); Output: C 2, public int codepointat (int index): Returns the character at the specified index (Unicode code point).      The index references a char value (Unicode code unit), which ranges from 0 to length ()-1.      int T=str.codepointat (2); System.out.println (t);      Output: 99 3, public int codepointbefore (int index): Returns the character (Unicode code point) before the specified index, ranging from 1 to length.          int T1=str.codepointbefore (2); SYSTEM.OUT.PRINTLN (t1); Output: 98 4, public int codepointcount (int beginindex,int endIndex): Returns the number of Unicode code points in the specified text range of this String, beginning with the specified beginindex to     EndIndex-1 Place. int T2=str.codepointcount (0,2);   System.out.println (T2);           Output: 2 5, public int compareTo (string anotherstring): Compares two strings in dictionary order, which is based on the Unicode value of each character in the string.      int T3=str.compareto (STR1); System.out.println (T3); Output:-1 6, public int comparetoignorecase (string str): Compares two strings in a dictionary order, regardless of case. 7. public string concat (String str): connects the specified string to the end of this string.     If the length of the argument string is 0, this string object is returned.     String Str3=str.concat (STR1); System.out.println (STR3); Output Result: ABCDEFGBCDEFG 8, public boolean contains (charsequences): Returns True if and only if this string contains a specified sequence of char values, as long as there is a containing, but is to be contiguous, case-sensitive.        Boolean str4=str.contains (STR1); System.out.println (STR4); Output: True 9, public boolean contentequals (Charsequence CS): Compares this string to the specified charsequence.                The result is true when and only if this String represents the same sequence of char values as the specified sequence.        Boolean s=str.contentequals (STR1); System.out.println (s);               Output: False 10, public boolean endsWith (string suffix): Tests whether this string ends with the specified suffix, or true if the argument is an empty string or equals this string object.        Boolean t=str.endswith (STR1); System.out.println (t); Output: True 11, public boolean equals (object AnObject): Compares this string to the specified object.             The result is true if and only if the parameter is not NULL and is a String object that represents the same sequence of characters as this object.       Boolean t1= str.equals (STR1); SYSTEM.OUT.PRINTLN (t1); Output: False 12, Boolean equalsignorecase (String anotherstring): Compares this string to another string, regardless of the case.        13. Static string Format (String format,object. Args): Returns a formatted string using the specified format string and parameters.        String S1=str.format ("%e", 2.22); System.out.println (S1); Output results: 2.220000e+00 14, public byte[] GetBytes (): The default character set encodes this String into a byte sequence and stores the result in a new byte array, resulting in a byte array.       Byte[] bytes= str.getbytes (); System.out.println (bytes); Output: [[email protected] 15, public void getChars (int srcbegin,int srcend,char[] dst,int dstbegin): The first character to be copied is located in the Srcbegin; The last character to be copied is located at srcEnd-1.       To copy to the DST sub-array, start at Dstbegin, Char t[]={' k ', ' l ', ' m ', ' n ', ' o ', ' P '};       Str.getchars (1,3,t,1); System.out.println (t);       Output: Kbcnop 16, public int hashcode (): Returns the hash code for this string.       int X=str.hashcode (); SYSTEM.OUT.PRINTLN (x);     Output:-1206291356 17, int indexOf (int ch): Returns the index of the first occurrence of the specified character in this string, and returns the index of the first occurrence of the character.     int X1=str.indexof (99); SYSTEM.OUT.PRINTLN (x1);        Output: 2 18, public int indexOf (int ch,int fromIndex): Returns the index at the first occurrence of the specified character in this string, starting the search from the specified index.        int X2=str.indexof (99, 1); System.out.println (x2); Output: 2 19, public int indexOf (string str): Returns the index where the specified substring first appears in this string. 20, public int indexOf (String str, int fromIndex): Returns the index of the first occurrence of the specified substring in this string, starting at the specified index. 21. Public Boolean IsEmpty (): When and only if length () Returns true for 0 o'clock. 22, public int lastIndexOf (int ch): Returns the index of the specified character at the last occurrence in this string. 23, public int lastIndexOf (int ch,int fromIndex): Returns the index of the last occurrence of the specified character in this string, starting at the specified index to reverse-search. 24, public int lastIndexOf (string str): Returns the index of the rightmost occurrence of the specified substring in this string. 25, public int lastIndexOf (String st,int FromIndex): Returns the index of the last occurrence of the specified substring in this string, starting at the specified index to reverse the search. 26, public int length (): Returns the length of this string.              27. public string Replace (char Oldchar,char Newchar): Returns a new string that is obtained by replacing all OldChar that appear in this string with Newchar.       String s3= str.replace (str, str1); System.out.println (S3);              Output: BCDEFG 28, public boolean startsWith (string prefix): Tests whether this string starts with the specified prefix, or returns True if the argument is an empty string or equals this string object.        Boolean s5=str.startswith (STR1); System.out.println (S5);        Output: False 29, public boolean StartsWith (String Prefix,int toffset): Tests whether the substring starting at the specified index begins with the specified prefix.        Boolean S6=str.startswith (STR1, 1); System.out.println (S6); Output: True 30, public string substring (int beginindex): Returns a new string that is a substring of this string.        The substring starts at the character at the specified index until the end of the string. StrinG s7=str.substring (5); System.out.println (S7); Output: FG 31, public string substring (int beginindex,int endIndex): Returns a new string that is a substring of this string. The substring starts at Beginindex until the index is endIndex-1.     32. Public String toLowerCase (): Converts all characters in this string to lowercase.     String str= "ABCD";     String s9=str.tolowercase (); System.out.println (S9); Output: ABCD 33, public string toUpperCase (): Converts all characters in this string to uppercase.     34, public string trim (): This string removes the leading and trailing blanks, and returns this string if there are no leading and trailing blanks.     String str= "abc" string A2=str.trim (); SYSTEM.OUT.PRINTLN (A2);  Output Result: ABC 1

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Common methods in the String class