systemverilog和verilog的区别

队列同样可以保存类对象，这在验证环境中是非常有用的，下面是一个例子:

 class animals;
    string sname;
    int i1;
    function new (string name="UN");
        sname = name;
        i1++;
    endfunction
 endclass
 
 module tb;
 // queue of class type 'animals'
 animals alist [$];
 initial begin
    animals f, f2; //declare two variables of type animals
    // Create a new class object 'f' and push into the queue
    f = new ("lion");
    alist.push_front (f);
    // Create another class object 'f2'and push into the queue
    f2 = new ("tiger");
    alist.push_back (f2);
    // Iterate through queue and access each class object
    foreach (alist[i]) begin
        $display ("alist[%0d] = %s", i, alist[i].sname);
        $display ("alist[%0d] = %p", i, alist[i]);
    end
    // Simply display the whole queue
    $display ("alist = %p", alist);
 end
 endmodule

仿真log:

# KERNEL: alist[0] = lion
# KERNEL: alist[0] = '{sname:"lion", i1:1}
# KERNEL: alist[1] = tiger
# KERNEL: alist[1] = '{sname:"tiger", i1:1}
# KERNEL: alist = '{'{sname:"lion", i1:1}, '{sname:"tiger", i1:1}}

该示例声明了一个名为“animals”的类，字符串“name”初始化为“UN”。

声明了两个“animals”类型的对象" f "和“f2”。

创建“animals”类型的对象队列“alist”。

分别实例化两个对象“f”和“f2”，然后push到队列中。