How To Count Occurrences Of Each Character In String In Java?
package govind_java;
import java.util.HashMap;
import java.util.Map;
public class EachCharacterCountInString {
public static void eachCharCountInString(String str)
{
//Creating a HashMap, key :Character value : occurrences as Integer
Map<Character, Integer> map=new HashMap<>();
//Converting inputString to char array
char[] kk = str.toCharArray();
//traversal of each Character of charArray
for(char t:kk)
{
if(map.containsKey(t))
{
//If char is present in map, increment count by 1
map.put(t, map.get(t)+1);
}
else
{
//If char is not present in map,
//Putting this char to map with 1 as it's initial value
map.put(t, 1);
}
}
System.out.println(map);
}
public static void main(String[] args) {
EachCharacterCountInString.eachCharCountInString("javatechnology");
}
}
o/p:----------------------------
{a=2, c=1, t=1, e=1, v=1, g=1, h=1, y=1, j=1, l=1, n=1, o=2}
How To Find Duplicate Characters In A String In Java?
package govind_java;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
public class DuplicateCharacterInString {
public static void duplicateCharacterInString(String str)
{
Map<Character, Integer> map=new LinkedHashMap<>();
char[] kk = str.toCharArray();
for(char ch:kk)
{
if(map.containsKey(ch))
{
map.put(ch, map.get(ch)+1);
}
else
{
map.put(ch, 1);
}
}
Set<Character> keyset = map.keySet();
System.out.println(keyset);
for(Character ch:keyset)
{
if(map.get(ch)>1)
{
System.out.println(ch +" : "+ map.get(ch));
}
}
}
public static void main(String[] args) {
DuplicateCharacterInString .duplicateCharacterInString("javatechnology");
}
}
o/p:------------------
[j, a, v, t, e, c, h, n, o, l, g, y]
a : 2
o : 2
Ist approach:-
package govind_java;
public class GetFirstNonRepeatingCharacterInString {
public static Character getFirstNonRepeatingCharacterInString(String str)
{
char[] ch = str.toCharArray();
for(int i=0;i<ch.length;i++)
{
if(str.lastIndexOf(ch[i])==str.indexOf(ch[i]))
return ch[i];
}
return null;
}
public static void main(String[] args) {
Character t = GetFirstNonRepeatingCharacterInString.getFirstNonRepeatingCharacterInString("javatechnology");
System.out.println(t);
}
}
o/p:-------------
j
2nd approach:-
package govind_java;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
public class GetFirstNonRepeatingCharThroughMap {
public static Character getFirstNonRepeatingCharThroughMap(String str)
{
Map<Character, Integer> map=new LinkedHashMap<>();
char[] kk = str.toCharArray();
for(char ch:kk)
{
if(!map.containsKey(ch))
{
map.put(ch,1 );
}
else
{
map.put(ch,map.get(ch)+1);
}
}
for(Entry<Character, Integer> cc:map.entrySet())
{
if(cc.getValue()==1)
return cc.getKey();
}
return null;
}
public static void main(String[] args) {
Character mmm = GetFirstNonRepeatingCharThroughMap.getFirstNonRepeatingCharThroughMap("javatechnology");
System.out.println("First Non Repeating Char="+mmm);
}
}
o/p:---------------------------------------------------
First Non Repeating Char=j
Wap to find all substring in java?
package govind_java;
public class FindAllSubStringInJava {
public void findAllSubStringInJava(String str)
{
for(int i=0;i<str.length();i++)
{
for(int j=i+1;j<=str.length();j++)
{
System.out.println(str.substring(i,j));
}
}
}
public static void main(String[] args) {
FindAllSubStringInJava fasj=new FindAllSubStringInJava();
fasj.findAllSubStringInJava("javatechnology");
}
}
o/p:---------------
j
ja
jav
java
javat
javate
javatec
javatech
javatechn
javatechno
javatechnol
javatechnolo
javatechnolog
javatechnology
a
av
ava
avat
avate
avatec
avatech
avatechn
avatechno
avatechnol
avatechnolo
avatechnolog
avatechnology
v
va
vat
vate
vatec
vatech
vatechn
vatechno
vatechnol
vatechnolo
vatechnolog
vatechnology
a
at
ate
atec
atech
atechn
atechno
atechnol
atechnolo
atechnolog
atechnology
t
te
tec
tech
techn
techno
technol
technolo
technolog
technology
e
ec
ech
echn
echno
echnol
echnolo
echnolog
echnology
c
ch
chn
chno
chnol
chnolo
chnolog
chnology
h
hn
hno
hnol
hnolo
hnolog
hnology
n
no
nol
nolo
nolog
nology
o
ol
olo
olog
ology
l
lo
log
logy
o
og
ogy
g
gy
y
Wap to check string is anagram or not?
package govind_java;
import java.util.Arrays;
public class AnagramProgram
{
static void isAnagram(String s1, String s2)
{
//Removing all white spaces from s1 and s2
String copyOfs1 = s1.replaceAll("\\s", "");
String copyOfs2 = s2.replaceAll("\\s", "");
//Initially setting status as true
boolean status = true;
if(copyOfs1.length() != copyOfs2.length())
{
//Setting status as false if copyOfs1 and copyOfs2 doesn't have same length
status = false;
}
else
{
//Changing the case of characters of both copyOfs1 and copyOfs2 and converting them to char array
char[] s1Array = copyOfs1.toLowerCase().toCharArray();
char[] s2Array = copyOfs2.toLowerCase().toCharArray();
//Sorting both s1Array and s2Array
Arrays.sort(s1Array);
Arrays.sort(s2Array);
//Checking whether s1Array and s2Array are equal
status = Arrays.equals(s1Array, s2Array);
}
//Output
if(status)
{
System.out.println(s1+" and "+s2+" are anagrams");
}
else
{
System.out.println(s1+" and "+s2+" are not anagrams");
}
}
public static void main(String[] args)
{
isAnagram("Mother In Law", "Hitler Woman");
isAnagram("keEp", "peeK");
isAnagram("SiLeNt CAT", "LisTen AcT");
isAnagram("Debit Card", "Bad Credit");
isAnagram("School MASTER", "The ClassROOM");
isAnagram("DORMITORY", "Dirty Room");
isAnagram("ASTRONOMERS", "NO MORE STARS");
isAnagram("Toss", "Shot");
isAnagram("joy", "enjoy");
}
}
o/p:----------------
Mother In Law and Hitler Woman are anagrams
keEp and peeK are anagrams
SiLeNt CAT and LisTen AcT are anagrams
Debit Card and Bad Credit are anagrams
School MASTER and The ClassROOM are anagrams
DORMITORY and Dirty Room are anagrams
ASTRONOMERS and NO MORE STARS are anagrams
Toss and Shot are not anagrams
joy and enjoy are not anagrams
Wap to reverse each word in string in java ?
package govind_java;
public class ReverseEachWordInString {
public void reverseEachWordInString(String str)
{
String[] kk = str.split(" ");
for(String t:kk)
{
System.out.println(t);
//Ist Way
/*StringBuilder sb=new StringBuilder(t);
sb.reverse();
System.out.print(sb);*/
//2nd way
String reverse="";
char[] ch = t.toCharArray();
for(int i=ch.length-1;i>=0;i--)
{
reverse=reverse+ch[i];
}
System.out.println(reverse);
}
}
public static void main(String[] args) {
ReverseEachWordInString rews=new ReverseEachWordInString();
rews.reverseEachWordInString("Govind Ballabh khan");
rews.reverseEachWordInString("java Technology");
}
}
o/p:-----------------
Govind
dnivoG
Ballabh
hballaB
khan
nahk
java
avaj
Technology
ygolonhceT
Wap to reverse string in java ?
package govind_java;
public class ReverseString {
public static String reverseString(String str)
{
char[] kk = str.toCharArray();
String reverse="";
for(int i=kk.length-1;i>=0;i--)
{
reverse=reverse+kk[i];
}
return reverse;
}
public static void main(String[] args) {
String yy = reverseString("java technology");
System.out.println("Reverse String="+yy);
}
}
o/p:--------------
Reverse String=ygolonhcet avaj
