Closure and lid and method of forming closure and lid

An example lid assembly (100) can include a lid and a slider (102). The lid can include a wall (118) defining a recess (122). The slider can be configured to slide in the recess and can be configured to move between a closed position where the slider covers the opening to aid in preventing spilling of contents of the container and an opened position where the slider uncovers the opening such that the contents of the container can be consumed. The slider can be configured to be removable from the lid and can be replaced back on the lid. Additionally, the slider can be formed from upper and lower sled elements that are magnetically coupled to one another. The problem to be solved is the spilling of liquid when using conventional liquid containers or cups with slidable openings. The solution improves the reliability of spill-proof containers or cups.