The main advantage of school uniforms is that they provide a common identity in school. Another advantage is that the students look smart when they are all together. Finally, students whose parents cannot afford nice clothes look the same as everyone else, so do not feel inferior.
but students find also some disadvantages of a school uniform.
when you have to wear the same clothes as everyone else you don't have a chance to develop your personal taste. but the main reason why most students don't like school uniforms is that sometimes they are of horrible colours and styles.
so, it is clear that there are arguments in favour of school uniforms as ell as arguments against