title: d3.js filter from csv file using multiple columns
body: <p>I want to filter using multiple column values from csv. I first want to filter by city and then criticality columns. I would like to filter Criticality (high/medium/low).  </p>
  
  <p>How to filter using AND/OR ?</p>
  
  <p>City and Criticality are checkboxes and based on the selections i want to filter the data from the respective csv columns. looking at efficient way of filter.</p>
  
  <p>Can i have something like </p>
  
  <pre><code>(d["Criticality]=="High" || d["Criticality"]=="Low")
  </code></pre>
  
  <p>currently this is what i am doing:</p>
  
  <pre><code>var City="London";
   var strSevText="High";
  
      d3.csv("Status.csv", function(consdata) {
  
      var filtercitydata = consdata.filter(function(d, i) 
      { 
  
              if (d["City"] == City) 
              { 
                  return d; 
              } 
  
          })
  
      var filtersevdata = filtercitydata.filter(function(d, i) 
          { 
              if (d["Criticality"] == strSevText) 
              { 
                  return d; 
              } 
  
          })
  
        })
  </code></pre>
  
  <p>My CSV file data :</p>
  
  <pre><code>Application_Id,Application Name,Status,Name,City,Criticality
  200009,OARINK,RED,Jen,London,High
  200039,3000 DEALING,RED,Marc,London,High
  200044,KON,RED,Martin,London,High
  200067,D3 MATCHING,RED,Marc,London,Medium
  200070,Next Generation,RED,Marc,London,High
  200088,ONE,RED,Jonathan,London,High
  200097,R-CHECK,RED,Graham,Paris,High
  200097,D-CHECK-I,RED,Graham,Mumbai,Low
  200107,CON,RED,Cary Fel,Paris,High
  </code></pre>