A curriculum is an organized and structured framework for learning and teaching. It’s a developmental document that contains guidelines, aims and outcomes for students which are necessary to progress from the lowest to the highest levels of the educational process. The educational aims are operationalized values that are expressed through the educational levels and are associated with the expected results of the levels of achievement which are called the outcomes. These aims allow us to focus on the the learning objectives. The principle is the beginning or the basis which should be valued through the various fields of human activity. The didactic principles are focused on the various parts of the educational process such as the teaching process, the content, the learning process and the acquisition of information and some are focused on the student. A computer science curriculum of the Republic of Croatia, the Republic of Slovenia and the United Kingdom integrate the didactic principles in different ways. In the context of high-school first grade in the Republic of Croatia and the domain of computational thinking and programming shows the outcome of the content that leads to its realization and outlines the challenges that may arise in the process.