why use var in java

1/* Depending on what variables you want to declare */
2String hello = "hello"; //characters
3short one = 12;//shorter integers
4int two = 2000; //complete integer up too 32 bits
5long number = 2000000; //complete integer up to 64 bits
6float decimal = 1.512 //up to 7 decimal digits
7double million = 1.387892847395 //up tp 16 decmial digits
8Bool condition = true; // true or false
9char a = "a"; // unicode character

1int myVariable = 42;    //This is the most commonly used variable. Only use other variables if you have a good reason to.

1improve the readability of code for other developers who read the code. 
2In some situations