title: Modify a specific element's class height and width
body: <p>I have a list of elements where I would like to modify the CSS attributes <code>width</code> and <code>height</code> for the class of a single element.</p>
  
  <p>I have this HTML with the randomly generated classes <code>class1</code>, <code>class2</code>, <code>class3</code>, etc...</p>
  
  <pre><code>&lt;div class="gantt_row class1 white-grid-row"&gt;&lt;/div&gt;
  &lt;div class="gantt_row class2 white-grid-row"&gt;&lt;/div&gt;
  &lt;div class="gantt_row class1 white-grid-row"&gt;&lt;/div&gt;//I want to change the css class class1 width for this element only. 
  &lt;div class="gantt_row class1 white-grid-row"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>If I have </p>
  
  <pre><code>.class1{width: 33px;}
  </code></pre>
  
  <p>I would like to change it to </p>
  
  <pre><code>.class1{width: 40px;}
  </code></pre>
  
  <p>For instance, I have the element list</p>
  
  <pre><code>let ganttRows = $('.white-grid-row');
  
  let classesToKeep = ['gantt_row', 'task-parent', 'white-grid-row', 'odd'];
  for (let i = 0; i &lt; ganttRows.length; i++) {
    for (let j = 0; j &lt; ganttRows[i].classList.length; j++) {
      if (!classesToKeep.includes(ganttRows[i].classList[j])) {
        let className = ganttRows[i].classList[j];
        $("." + className).css('width', 33); //this changes the elements width, I need to change the width of class1
        //how can I modify class1 for this element only or replace the class with a copy of class1 except for the width
      }
    }
  }
  </code></pre>
  
  <p>How can I modify the height and width of that randomly generated class?</p>