Common string APIs in Java

Common string APIs in Java

These APIs are encapsulated in a

Import Java.lang; (default import does not need to be imported manually)

String. Length ()

Returns the length of a string

String 1.equals (String 2)

Determine whether the contents of two strings are consistent ( cannot be used = =)

String 1.equalsIgnoreCase (String 2)

Determine whether the contents of two strings are consistent (case insensitive)

String. toLowerCase ()

Returns a lowercase string

String. toUpperCase ()

Return uppercase String

String 1.concat (String 2)

Return string 1 to String 2 (equivalent to "string 1" + "String 2")

String 1. CompareTo (String 2)

Returns the value of string 1 compared to string 2 (each of which is the same as ASCII) returns 0

/** Common Extraction method (if not found return-1) */public int indexOf (char ch)/** Returns the first occurrence of the character Ch's position */public int indexOf (string value)/** returns the first occurrence of the string The position of value */public int indexOf (char ch)/** returns the position of the last occurrence of CH, */public int indexOf (string value)/** returns the position of the last occurrence of the string value */ public string substring (int index)/** extracts the string portion starting from the position index */public string substring (int beginindex,int endindex)/** extract from the starting position of the cable String part */public string trim ()/** Returns a copy of the call string without any spaces before the end position index (excluding the end position) */

/** Common Splitting method */
The/** string class provides the split () method to split a string into a substring result as an array of strings returned */

public class Demo {public  static void Main (string[] args) {     String std = "A,b,c";     string[] Strarray = Str.split (",");     /** Sometimes the split delimiter will conflict with the keyword of the regular expression, then escape a bit, such as Str.split ("\\|"); Use | as delimiter *     /for (String item:strarray) System.out.println (item);//output a B c  }}

Common string APIs in Java