Please help me how does the string.equals in java work with null value? Is there some problem with exceptions? Three cases:
boolean result1,result2, result3;
//1st case
String string1 = null;
String string2 = null;
result = string1.equals(string2);
//2nd case
String string1 = "something";
String string2 = null;
result2 = string1.equals(string2);
//3rd case
String string1 = null;
String string2 = "something";
result3 = string1.equals(string2);
What the values of results are? I expect this values:
result1 is true;
result2 is false;
result3 is false;
You cannot use the dereference (dot, '.') operator to access instance variables or call methods on an instance if that instance is null
. Doing so will yield a NullPointerException
.
It is common practice to use something you know to be non-null for string comparison. For example, "something".equals(stringThatMayBeNull)
.
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