Core-java-technical-Question-Program

                         Core java technical Question Program

String only program

1. How do you count the number of occurrences of each character in a string?
    
      val str="karun kumar"
      val ch=str.toCharArray()
      val map=HashMap<Char,Int>()
   
      for(i in ch){
         if(map.containsKey(i)){
         map.put(i, map[i]!! +1)
        }else map.put(i,1)
       }
      map.forEach { k, v -> println(" Key: $k --  Values: $v")}
   

2. How do you remove all white spaces from a string in java?
   
    val str="karun kumar Singh"
     for(i in 0..str.length-1){
      if(str[i] !=' '){
         print(str[i])
      }
    }
   

3. How do you covert to string to array? 
   
     * val str="This is Ram"
      val sb=str.split(" ")
      for (i in 0..sb.size-1){
      println(sb[i])
      }
   

4. Write a java program to reverse a string and without using reverse()?
        
    * val str="karun"
      for(i in str.length-1 downTo 0){
      print(str[i])
      }
    * val sb=StringBuilder(str)
      print(sb.reverse())
   

5. Write a java program to count word a string?  
   
   var count=1
   val str="This is Mohan"
   for (i in 0.. str.length-1) {
     if(str[i]==' ')
      count++
    }
   println("Total Words:"+ count)
   

6. Write a Java program to find the length of a String without using inbuilt functions.
    var count=0
    val str="This is Ram"
    for (i in str.toCharArray()) {
      count++
    } 
    println(count)
   

7.  Write a java program to reverse each word of a given string?
     val str="This is Mohan"
     val s=str.split(' ')
     for (i in s.size-1 downTo 0) {
       print(" " +s[i])
     }   
     
     output-> Mohan is This
   

8.  Write a program to check if a String is a palindrome in Java? 
   
    val str="madam"
    var rev=""
     for (i in str.length-1 downTo 0) {
        rev+=str[i]
     }
     if(str==rev){
         println("this is a palindrome : "+str)
     } else  println("this is Not palindrome :"+str)
   

9.   How do you convert string to integer and integer to string in java?
   
    * val str:String="12"
      val a:Int=34
      val c:Int=a+Integer.parseInt(str)
      print(c)
   

10. Write a java program to check whether two strings are anagram or not?
    
     val str1="karun"
     val str2="arun"
    
     val s1 = str1.replace("\\s", "");
     val s2 = str2.replace("\\s", "");
    
     var status = true;
         if(s1.length != s2.length)
             status = false;
         else
         {
             val arr1 = s1.toLowerCase().toCharArray();
             val arr2 = s2.toLowerCase().toCharArray();
             Arrays.sort(arr1);
             Arrays.sort(arr2);
             status = Arrays.equals(arr1, arr1);
         }
    
      if(status)
             System.out.println(s1+" and "+s2+" are anagrams");
         else
             System.out.println(s1+" and "+s2+" are not anagrams");
    

11. Write a Java program to find first non repeated character in a string.
    

12. Write a Java program to check  if given strings are Isomorphic.