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2-ui/1-document/07-modifying-document/4-clear-elem/solution.md

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+
+First, let's see how not to do it:
+
+```js
+function clear(elem) {
+  for (let i=0; i < elem.childNodes.length; i++) {
+      elem.childNodes[i].remove();
+  }
+}
+```
+
+That won't work, because the call to `remove()` shifts the collection `elem.childNodes` every time, so elements every time start from index `0`. So `i` should not increase in the loop at all.
+
+The `for..of` loop also does the same.
+
+The right variant would be:
+
+```js
+function clear(elem) {
+  while (elem.firstChild) {
+    elem.firstChild.remove();
+  }
+}
+```
+
+And also there's a simpler variant:
+
+```js
+function clear(elem) {
+  elem.innerHTML = '';
+}
+```