/ * * Get the string length of the String.length () * string is case-sensitive comparison String.equals (String str) returns true or false * case-insensitive string comparison String.equalsIgnoreCase (String str); return true or false String.charAt * returns the character at the specified index (int index) * find a location String.indexOf parameter string is first found in the original string (string str) return to find the location of the index, not found returns -1 * string splicing String.concat (string str) returns a new string object after splicing * string during the program run, its value can not be changed. also called string constants. * string interception String.substring (int index) returned from subscript index start to end of the string * String.substring (int a, int b ) returns a string from the subscript b-1 start to the end of the subscript * * / Import java.sql.SQLOutput; public class StringDemo { public static void main (String [] args) { String STR = "Your the Begin challeging your own Assumptions Assumptions are your Windows ON OFF The World Scrub Them A Every Once in the while, or in The Light Will Not Come.." ; // Get string length System.out.println (str. length ()); // distinction is the case, two strings are equal System.out.println (str.equals ( "Hello" )); // not case-sensitive comparison whether the two strings are equal System.out. the println (str.equalsIgnoreCase ( "Hello" )); // get the first character of a value System.out.println (str.charAt (0 )); // Get the character subscript e System.out.println (str .indexOf ( "E" )); // find the specified character index, and returns the character string in the index, not found -1 System.out.println (str.indexOf ( 'C',. 3 )); // taken from the start to the end of the specified index string System.out.println (str.substring (10 )); // taken from the specified start index string to the end of the specified superscript -1 System.out.println (str.substring (10,15 )); } }