Question

I would like to use the following compact way to build a String:

String attributes = null;
for (Map.Entry<String, String> kvp : attrs.entrySet())
  attributes += (kvp.getKey() + "='" + kvp.getValue() +"' ");

but the result is a String which reads: nullattr1='val1' attr2='val2' attr3='val3'. I presume that this is happening as a result of performing a += operation on a String whose current value is null. Is there no compact way to do this without having to check if attributes is null each time through the loop?

Answer 1

Do this for initializing the String at the beginning of the code:

String attributes = "";