constraint natural number code and twice odd number code

 constraint natural number code:-

/*----------------natural no and twice odd no---------

class b1;

rand int a[];

constraint a1{a.size==(10);}

constraint a2{foreach (a[i])

                        if(i%2==0)

                            a[i]==i; // a[i]==i; // a[i]==i+1;

else if(i%2==1)

a[i]==i+1;}

endclass

b1 a3;

module test;

initial

begin

a3=new;

assert(a3.randomize());

$display("the value %p",a3.a);

end

endmodule

*/

constraint twice odd number code:-

/*class b1;

rand bit[7:0] a[];

constraint a1{a.size==(10);}

constraint a2{foreach (a[i])

                        if(i%2==0)

                                a[i]==i;}

endclass

b1 a3;

module test;

initial

begin

a3=new;

assert(a3.randomize());

$display("the value %d",a3);

end

endmodule*