string manipulation methods code example

Example 1: String manipulations

boolean eq = name.equals(anotherName);                // equality

String fruit = "Apple";
int position = fruit.indexOf("pp");                   // 1 (if not found, -1)

int length = fruit.length()                           // 5 (lenght)

String sub = fruit.substring(1, 4);                   // exp: (1. index get into, 4. index does not)

String upper = fruit.toUpperCase();                   // APPLE

boolean empty = fruit.isEmpty();                      // false, with empty string true
boolean blank = fruit.isBlank();                      // false, only true with white space character

boolean startsWith = fruit.startsWith("app");         // true
boolean endWith = fruit.endsWith("le");               // true
boolean containsDoubleP = fruit.contains("pp");       // true
String part = fruit.substring(0, 2).toLowerCase();    // ap - can be join

Example 2: string manipulation

String manipulations:
charAt(indexNumber): it returns the char at the given index
length(): returns the total number of characters as int
		length is ALWAYS one unit above the maximum index number
		maxIndex: length()-1;
concat(Value): Concatenation, concats the given value to the String and returns a new value
toLowerCase(): converts to lowercase and returns a new String
toUpperCase(): converts to uppercase and returns a new String
trim(): removes the unused spaces , and returns new String
substring(beginning index, ending index): 
creates substring of the string value from the beginning index till the ending                   
substring(beginning index): 
creates substring of the string value from the beginning index till the end of the stringreplace(old Value, new Value): new value will be replaced with ALL the given old value, and returns new string 
replaceFirs(old Value, new Value): 
new value will be replaced with  the very first given old value, and returns new string
indexOf(Value): 
returns the index number of the first occurred character as an int             
indexOf(Value): returns the index number of first occurred character, as int
lastIndexOf(Value): return the index number of last occurred character, as int
isEmpty(): identifies if the string is empty
                true ==> string is empty,
                false ==> String is not empty
equals(str): checks if two string' visible texts are equal or not
                    cares about the case sensitivity
                        A == a  ==> false
 equalsIgnoreCase(str):  checks if two string' visible texts are equal or not
                 does not care case sensitivity
                    A == a ==> true
 contains(str): checks if the str is contained in the string. returns boolean
                    if str is conatined ==> true
                    otherwise ==> false
 startsWith(str): checks if the string starts with the given str. returns boolean
                if starts with str ==> true
                otherwise ==> false
endsWith(str): checks if the string ended with the given str. returns boolean
                 if ended with str ==> true
                    otherwise ==> false