Equal height of columns in Bootstrap 4

Question

I have a little non-conventional DIV in this design as shown below. I could use a height and do it but I want it to change dynamically: For instance, if the DIV has more content and the height changes in one of the block on the right, the left DIV auto adjust it's height as well. I wonder if flex could help. Here's how it should change to:

I have this HTML so far:

<div class="container">
  <div class="row row-eq-height">
      <div class="col-sm-8 col-8">
        <div class="black">
          <p>Bar Graph or Line Graph</p>
        </div>
      </div>
      <div class="col-sm-4 col-4">
        <div class="red">
          <p>numbers</p>
        </div>
        <div class="purple">
          <p>numbers</p>
        </div>
        <div class="green">
          <p>numbers</p>
        </div>
        <div class="blue">
          <p>numbers</p>
        </div>
      </div>
  </div>
</div>

and CSS:

p { color: #fff; }
.black { background-color: black; }
.green { background-color: green; }
.red { background-color: red; }
.blue { background-color: blue; }
.purple { background-color: purple; }

JSFiddle Demo

Answer 1

You can use flexbox for this.

Update

And another way:

https://jsfiddle.net/persianturtle/ar0m0p3a/5/

.row-eq-height > [class^=col] {
  display: flex;
  flex-direction: column;
}

.row-eq-height > [class^=col]:last-of-type div {
  margin: 10px;
}

.row-eq-height > [class^=col]:last-of-type div:first-of-type {
  margin-top: 0;
}

.row-eq-height > [class^=col]:last-of-type div:last-of-type {
  margin-bottom: 0;
}

.row-eq-height > [class^=col]:first-of-type .black {
  flex-grow: 1;
}

Update

A better way with more specific classes:

https://jsfiddle.net/persianturtle/ar0m0p3a/3/

.row-eq-height > [class^=col]:first-of-type {
  display: flex;
}

.row-eq-height > [class^=col]:first-of-type .black {
  flex-grow: 1;
}

.blue p {
  margin: 0;
}

Original way:

https://jsfiddle.net/persianturtle/ar0m0p3a/1/

[class^=col] {
  display: flex;
  flex-direction: column;
}

[class^=col] div {
  flex-grow: 1
}