- Qt 6.4
- Qt QML
- QML Script Compiler
- Qt 6.4.3 Reference Documentation

# QML Script Compiler

## Limitations when compiling JavaScript

Many JavaScript constructs cannot be efficiently represented in C++. qmlsc skips the C++ code generation for functions that contain such constructs and only generates byte code to be interpreted. Although, most common QML expressions are rather simple: value lookups on QObjects, arithmetics, simple if/else or loop constructs. Those can easily be expressed in C++, and doing so makes your application run faster.

qmlsc is available for commercial customers and some of its features are merged into qmlcachegen, which continues to be available with all versions of Qt.