Common Operations on strings)

Indexof-search function
Int string. indexof (string value );
Returns the position of the first occurrence of a substring in a string, starting from 0. If no substring is found,-1 is returned.
Int string. indexof (string value, int startindex );
Same as above, but searches from the startindex position of the string until the end of the string.
Int string. indexof (string value, int startindex, int count );
Same as above, but starts from the specified position of the string and searches back for Count characters.
Note that the values of the last two parameters must meet the following conditions: 0 <= startindex <Length 0 <count <= length-startindex
Example: String mystr = "abcabcabc ";
Expression	Return Value
Mystr. indexof ("")	-1 // case sensitive
Mystr. indexof ("")	0
Mystr. indexof ("A", 0)	0 // the index of the first character is 0
Mystr. indexof ("A", 1)	3
Mystr. indexof ("A", 1, 2)	-1
Mystr. indexof ("A", 1, 3)	3 // search for a total of Count characters

Lastindexof-reverse search function

Returns the position of the last occurrence of the substring in the string, from the back to the front.

0 <= startindex <Length 0 <count <= startindex + 1

Insert-insert Function

String insert (INT startindex, string value );

Insert a string at the specified index position of the string. In the returned string, the index number of the first character of the value string is startindex.

Remove-delete a function

String remove (INT startindex, int count );

Deletes a specified number of characters from the specified index position of a string. The index and Count must reference the position in the string, startindex + count <= Length

Replace-replace Function

String Replace (char oldchar, char newchar );

String Replace (string oldvalue, string newvalue );

Concat-connection Function

String Concat (parameter );

Parameters can be objects, object arrays, strings, and string arrays. Multiple objects (strings) are separated by commas (,).

Join-concatenation Function

String join (string separator, string [] value );

Concatenates the specified separator between each element of the string array to generate a single concatenation string.

String join (string separator, string [] value, int startindex, int count );

Concatenates some array elements, starting from the startindex element, and concatenates count elements.

Split-split Function
String [] Split (Params char [] separator );
Splits the string into substrings Based on the delimiter, and returns the result as a string array.
String [] Split (char [] separator, int count );
The Count parameter specifies the maximum number of returned array elements for partial segmentation.
Example: String mystr = "1 + 2 + 3-4 + 5 + 6 ";
Expression	Return
Mystr. Split ('-');	{"1 + 2 + 3", "4 + 5 + 6 "}
Mystr. Split ("+-". tochararray ());	{"1", "2", "3", "4", "5", "6 "}
Mystr. Split (New char [] {'+ ','-'});	{"1", "2", "3", "4", "5", "6 "}
Mystr. Split ("+-". tochararray (), 4 );	{"1", "2", "3", "4 + 5 + 6 "}
MySQL. Split ("+-". tochararray (), 100 );	{"1", "2", "3", "4", "5", "6 "}
Note the usage of the delimiter At most count elements are returned for partial splitting.

tochararray-scatter function (Haha, I borrowed the term in Flash)
char [] tochararray ();
copy the characters in the string to the character array.
char [] tochararray (INT startindex, int length);
copy the characters in the specified substring to the character array.
example: String mystr = "diffmaker";
Expression	return
mystr. tochararray ();	{'D', 'I', 'F', 'F', 'M', 'A', 'k ', 'E', 'R'}
mystr. tochararray (4, 4);	{'M', 'A', 'k', 'E'}

Trim | trimstart | trimend-trim Function

String trim (); // remove the leading and trailing white spaces (including Chinese and English spaces) from the string)

String trimstart (); // removes the string header space (including Chinese and English spaces)

String trimend (); // Remove trailing white spaces (including Chinese and English spaces) from the string)

String trim (Params char [] trimchars); // remove the first and last characters of the string

String trimstart (Params char [] trimchars); // remove the first character of the string

String trimend (Params char [] trimchars); // remove the tail character of the string

When no parameter is specified, blank characters are removed. When a parameter is specified, the specified character is removed.

Startswith | endswith-endpoint Function

Bool startswith (string value); // checks whether the string starts with a substring.

Bool endswith (string value); // checks whether the string ends with a substring.

Padleft | padright-Fill function

String padleft (INT totalwidth); // Add a space on the left side of the string to reach the specified length.

String padright (INT totalwidth); // Add a space to the right of the string to reach the specified length

String padleft (INT totalwidth, char paddingchar); // Add the specified character to the length on the left

String padright (INT totalwidth, char paddingchar); // Add the specified character to the right to the fixed length

Substring-subfunction

String substring (INT startindex); // starts from the specified character position to the end of the string

String substring (INT startindex, int length); // obtain the specified length from the specified character position

Startindex starts from scratch If startindex is equal to the length of the string, return: String. Empty Startindex + count <= Length

Other simple functions

String. tolower (); // converts the string to lowercase.

String. toupper (); // convert to uppercase