title: What is the usage of const in the following lines, and what if we donot use those quants?
body: <pre><code>//Array-based Class ‘LinearList’
  template &lt;class T&gt;
  class LinearList 
  {
  public: 
    LinearList(int MaxListSize = 10);
    ~LinearList() { delete [] element; }
  
    bool isEmpty() const { return length == 0; } //1
    int Length() const { return length; } //2
    bool Find(int k, T&amp; x) const; //3
    int Search(const T&amp; x) const; //4
    LinearList&lt;T&gt;&amp; Delete(int k, T&amp; x);
    LinearList&lt;T&gt;&amp; Insert(int k, const T&amp; x); //5
    void Output(ostream&amp; out) const; //6
  
  private: 
    int length;
    int MaxSize;
    T *element;
  };
  </code></pre>