The concept of "21st century skills" has entered our lives in the recent past and has been used to describe the skills that our children should be equipped with while preparing them for the future world. Coding skill, in this regard, is seen as a new 21st century skill that is assumed to be a part of logical reasoning. The main purpose of the present research is to examine the use of coding-based interventions in learning environments from various perspectives and reveal their effects on student attitudes in detail with a research synthesis based on the mixed-meta method. Primarily, a quantitative metaanalysis was used to determine the effects of coding-based practises on student attitudes. Another process that will enrich the content reached in the study and add a qualitative dimension to it is the meta-thematic analysis stage. As a result of the meta-analysis, the effect size reached is moderate (g = 0.555), and the effect of the related practises on the learners' attitude scores is positive. As a result of the meta-thematic analysis carried out in order to further consolidate the findings of the meta-analysis, five major themes emerged: the effect of coding-based instruction on the cognitive dimension, its effect on the affective dimension, its contribution to 21st century skills, its contribution to personal and professional development, and difficulties encountered in coding-based instruction.