java count frequency of characters in a string code example
Example 1: java count frequency of characters in a string
public class Frequency
{
public static void main(String[] args) {
String str = "picture perfect";
int[] freq = new int[str.length()];
int i, j;
//Converts given string into character array
char string[] = str.toCharArray();
for(i = 0; i
Example 2: find the frequency of characters in a string in java
+++METHOD WITH NONDUP+++
public static String FrequencyOfChars(String str) {
String nonDup = "";
for(int i=0; i < str.length(); i++)
if(!nonDup.contains(""+str.charAt(i)))
nonDup+= ""+str.charAt(i);
String expectedResult = "";
for( int j=0;j < nonDup.length(); j++) {
int count = 0;
for(int i=0; i < str.length(); i++) {
if(str.charAt(i) == nonDup.charAt(j))
count++;
}
expectedResult +=nonDup.charAt(j)+"" + count;
}
return expectedResult;
}
+++METHOD WITH REPLACE METHOD+++
public static String FrequencyOfChars(String str) {
String expectedResult = "";
for( int j=0; j < str.length(); j++) {
int count = 0;
for(int i=0; i < str.length(); i++) {
if(str.charAt(i) == str.charAt(j)) {
count++;
}
}
expectedResult +=str.charAt(j)+"" + count;
str = str.replace(""+str.charAt(j) , "" );
}
return expectedResult;
}
+++WITH LINKED HASH SET+++
public static String FrequencyOfChars(String str) {
String b=new LinkedHashSet<>(Arrays.asList(str.split(""))).toString();
b = b.replace(", ","").replace("[","").replace("]","");
String result="";
for(int j=0; j
Example 3: get frequency of letters java
HashMap map = new HashMap();
String s = "aasjjikkk";
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
Integer val = map.get(c);
if (val != null) {
map.put(c, new Integer(val + 1));
}
else {
map.put(c, 1);
}
}