Celsius to Fahrenheit :

package com.hitarth;
import java.util.Scanner;
public class L7_Temperature {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        System.out.print("Enter the temp(in °C): ");
        float tempC = input.nextFloat();

        float tempF = tempC*9/5 + 32;
        System.out.println(tempF);
    }
}

String

1. Palindrome :

Method 1 : Using String Builder

package com.hitarth;

import java.util.Scanner;

public class temp {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        StringBuilder stb = new StringBuilder(input.next());

        StringBuilder rev = new StringBuilder(stb).reverse();

        if(stb.toString().equals(rev.toString()))
            System.out.println("Palindrome is the");
        else
            System.out.println("Not a Palindrome");

    }
}

Method 2 : Using String

package com.hitarth;

import java.util.Scanner;

public class temp {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        String str = input.next();
        int s = 0;
        int e = str.length()-1;
        int flag=0;

        System.out.println();
        while ( s<= e )
        {
            if (str.charAt(s) != str.charAt(e))
            {
                flag++;
                break;
            }
            s++;
            e--;
        }
        if(flag == 1)
            System.out.println("Not a palindrome");
        else
            System.out.println("Palindrome is the");
    }
}