Memory efficient way to initialize a String to be reused inside a loop

Question

I'm using a couple of Strings in my code that are going to be reused within a loop and I'm wondering what would be the best way to initialize the String variables to improve memory usage:

// Just for sample purposes I will declare a Map, but the same thing
// applies for an ArrayList, Database Set, etc. You get the point.
Map<String, String> sampleMap = getMap();
int mapSize = sampleMap.size();

// String initialization
String a;
String b = new String();
String c = "";

for(int i = 0; i < mapSize; i++){
    a = sampleMap.get(i);
    b = someFunc(a);
    c = anotherFunc(a);
    // Do stuff with all the Strings
}

After the loop, the Strings are no longer used.

Answer 1

Reduce the scope of your variables to restrict them to where they are used:

// Just for sample purposes I will declare a Map, but the same thing
// applies for an ArrayList, Database Set, etc. You get the point.
Map<String, String> sampleMap = getMap();
int mapSize = sampleMap.size();

for(int i = 0; i < mapSize; i++){
    String a = aFunc();
    String b = sampleMap.get(i);
    String c = anotherFunc();
    // Do stuff with the Strings
}

There is no performance benefit of declaring the variables outside the loop.