JavaInterviewPrograms

Find a letter or String in a String:

String a = "santosh kumar Gaddam";

a.length();                

System.out.println(a.contains("kumar")); // find a word from given string using in-build method

for(int i=0; i

if(a.charAt(i) == 'n') {

System.out.println("found n at : " + i); //find a letter

break; //break the for loop

}

}

//Find a number in Array

int a[] = {1,2,3,4,5};

int find = 4;

for(int i=0; i

if(a[i]==find){

System.out.println("number found");

System.out.println("position of the number is : "+i);

break;

} else {

System.out.println("not found at : " + i);

}

}

//Find a Large number from an array.

int a[] = {10,1,3,8,50};

int large=a[0];

for(int i=0; i

if(a[i]>large) {

large = a[i];

}

}                

System.out.println("large number is : "+large);

//Find a Low/Minimum number from an array

int a[] = {10,1,3,8,50};

int low=a[0];

for(int i=0; i

if(a[i]

low = a[i];

}

}                

System.out.println("low number is : "+low);                

//Get the index of a 'n' number from an array

int a[] = {1,2,3,4,5,6,7,8,9,0};

int pos=7;

for(int i=0; i

if(a[i] == 7) {

System.out.println(i);

break; // use this break to exist the loop

}

}

//String Reverse

int itr = 0;

String str = "santosh";

String store[] = new String[strlen];

char c;

String temp;

for(int j=str.length()-1;j>0;j--) {                        

System.out.println(str.charAt(j));

c = str.charAt(j);

temp = Character.toString(c);

store[j] = temp;

itr++;

}

System.out.println(store.length);

for(int k=0; k

System.out.println(store[k]);

}

Or

 String str = "Saket Saurav";

  char chars[] = str.toCharArray();  // converted to character array and printed in reverse order

  for(int i= chars.length-1; i>=0; i--) {

        System.out.print(chars[i]);

  }

//Swap the values without using a third variable.

x=100;

y=200;

x=x+y; //300

y=x-y; //300-200=100

x=x-y; //300-100=200

//Count the repeated strings using HashMap

String str = "This this is is done by Saket Saket";

String[] strSplit = str.split(" ");

HashMap map = new HashMap<>();

for(int i=0; i

if(map.containsKey(strSplit[i])) {

int count = map.get(strSplit[i]);

map.put(strSplit[i], count+1);

} else {

map.put(strSplit[i], 1);

}

}

System.out.println(map);

Output: {Saket=2, by=1, this=1, This=1, is=2, done=1}

//Given Number Prime or not

int num = 83;

boolean primeRes = true;

for(int i=2; i

int res = num%i;

System.out.println(res);

if(res == 0){

primeRes = false;

break;

}                        

}

System.out.println(primeRes);

//Fibonaci series

int a,b,c;

a=0;

b=0;

c=1;

for(int i=0; i<10 i="" p="">

a = b;

b = c;

c = a+b;

System.out.println(c);

}

//Print ArrayList in 3 modes while, for and for with object

ArrayList al = new ArrayList<>();

al.add(10);

al.add(20);

al.add(30);

al.add(40);

Iterator it = al.iterator();

while(it.hasNext()){

System.out.println(it.next());

}

for(int i=0; i

System.out.println(al.get(i));

}

for(Object i: al){

System.out.println(i);

}

// Find repeated/duplicate values from a string.

String name = "santoshkumargaddam";

char[] chr = name.toCharArray();

Set st = new HashSet<>();

for(int i=0; i

for(int j=i+1; j

if(chr[j] == chr[i]) {

st.add(Character.toString(chr[j]));

}

}

}

System.out.println(st);

Or use below program

String name = "santosh kumar gaddam";

char[] chr = name.toCharArray();

for(int i=0; i

for(int j=i+1;j

if(chr[i] == chr[j]){

System.out.println(chr[i]);

}

}

}

//Large Number from array and second large number from array.

int[] a = {1,4,1,6,3,2,1,9,2,3,8,0};

int largeNumber = 0;

int secondlargeNumber = 0;

for(int i=0; i

if(a[i] > largeNumber ) {

secondlargeNumber = largeNumber;

largeNumber = a[i];

} else if(a[i] > secondlargeNumber) {

secondlargeNumber = a[i];

}

}

System.out.println(largeNumber);

System.out.println(secondlargeNumber);                

// Remove the spaces and tabs from a given string

String name = "T hi is  Santo sh Kum ar Ga        ddam";

StringBuffer sb = new StringBuffer();

char[] chr = name.toCharArray();

for(int i=0; i < chr.length; i++){

if(chr[i] != ' ' && chr[i] != '\t'){

sb.append(chr[i]);

}                

}

System.out.println(sb);

//check the given number ArmStrong number not ?

int armstg = 153;

int temp = armstg;

int a,sum,n;

sum=0;

n=armstg;

while(n>0) {

a = n%10;

n = n/10;

sum = sum + (a*a*a);

}                

System.out.println(sum);

if(temp == sum) {

System.out.println("Arm Strong Number");

} else {

System.out.println("it's not a Arm String Number");

}