- Qt 6.12
- Qt Qml
- QML Lint Warning and Errors
- Components must have exactly one child
- Qt 6.12.0 Reference Documentation

# Components must have exactly one child

This warning category is spelled `[component-children-count]` by qmllint.

## Components must have exactly one child

### What happened?

A Component has the wrong number of children. It must have exactly one.

### Why is that bad?

The root component of the file won't be instantiable and will cause an error at runtime.

### Example

     Component {
         Rectangle {
             width: 50
             height: 50
             color: "red"
         }
         Rectangle {
             width: 50
             height: 50
             color: "blue"
         }
     }

To fix this warning, make sure the component has exactly one child. If it is empty, add a child to it. If it contains multiple, either remove the excess children, or wrap the children into a single top-level child of the component.

     Component {
         Item {
             Rectangle {
                 width: 50
                 height: 50
                 color: "red"
             }
             Rectangle {
                 width: 50
                 height: 50
                 color: "blue"
             }
         }
     }