String (java.lang.String)

• Immutable
• String APIs

package com.example;

import java.util.Arrays;

public class StringTest {
  public static void main(String... args) {
    String str = "  some random String to-try in java  . ";
    String replacedString = str.replace(" ","");

    // String APIs
    System.out.printf("Str        : '%s'\n", str);
    System.out.printf("toLowerCase: '%s'\n", str.toLowerCase());
    System.out.printf("toUpperCase: '%s'\n", str.toUpperCase());
    System.out.printf("trim       : '%s'\n", str.trim());
    System.out.printf("length     : '%s'\n", str.length());
    System.out.printf("bytes      : '%s'\n", Arrays.toString(str.getBytes()));
    System.out.printf("replace    : '%s'\n", str.replace(" ",""));
    System.out.printf("startswith : '%s'\n", replacedString.startsWith("some"));
    System.out.printf("endswith   : '%s'\n", replacedString.endsWith("some"));
    System.out.printf("split      : " + Arrays.toString(str.split("-")) + "\n");
    System.out.printf("charAt     : '%s'\n", str.charAt(2));
    System.out.printf("contains   : '%s'\n", str.contains("random"));
    System.out.printf("indexOf s  : '%s'\n", str.indexOf('s'));
    System.out.printf("lastIndexOf: '%s'\n", str.lastIndexOf('s'));
    System.out.printf("toCharArray: "+Arrays.toString(str.toCharArray())+"\n");
    System.out.printf("blank      : '%s'\n", str.isBlank());
    System.out.printf("empty      : '%s'\n", str.isEmpty());
    System.out.printf("equals     : '%s'\n", str.equals("random"));
    System.out.printf("intern     : '%s'\n", str.intern());
  }
}
/*
Output
========
$ java com/example/StringTest.java
Str        : '  some random String to-try in java  . '
toLowerCase: '  some random string to-try in java  . '
toUpperCase: '  SOME RANDOM STRING TO-TRY IN JAVA  . '
trim       : 'some random String to-try in java  .'
length     : '39'
bytes      : '[32, 32, 115, 111, 109, 101, 32, 114, 97, 110, 100, 111, 109, 32, 83, 116, 114, 105, 110, 103, 32, 116, 111, 45, 116, 114, 121, 32, 105, 110, 32, 106, 97, 118, 97, 32, 32, 46, 32]'
replace    : 'somerandomStringto-tryinjava.'
startswith : 'true'
endswith   : 'false'
split      : [  some random String to, try in java  . ]
charAt     : 's'
contains   : 'true'
indexOf s  : '2'
lastIndexOf: '2'
toCharArray: [ ,  , s, o, m, e,  , r, a, n, d, o, m,  , S, t, r, i, n, g,  , t, o, -, t, r, y,  , i, n,  , j, a, v, a,  ,  , .,  ]
blank      : 'false'
empty      : 'false'
equals     : 'false'
intern     : '  some random String to-try in java  . '
*/

• API Docs - link
• Baeldung Java String Catalog - link