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class Test extends create{
public Test(int j){}/*if i comment this line it works perfectly why??*/
public Test(int j,int k){super(j,k); }
}
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When you declare public Test(int j){}
Compiler calls a no arg default constructor (super()) implicitly. As you do not have a default no arg constructor in create class the compilation fails.
You should explicitly create a no arg default constructor in create class or explicitly call super( j, k) in the first line of your code. public Test(int j){super(j,0);}/*
Note that if you do not create your own customized construtor
Java creates a default no arg constructor for you, but if you create one then the default no arg constructor is not created, so, create class do not have default no arg constructor.