In Go language slice is more powerful, flexible, convenient than an array, and is a lightweight data structure. The slice is a variable-length sequence which stores elements of a similar type, you are not allowed to store different type of elements in the same slice.
In the Go slice of bytes, you are allowed to convert a slice in the uppercase using ToUpper() function. This function returns a copy of the given slice of bytes(treat as UTF-8-encoded bytes) in which all the Unicode letters mapped into uppercase. It is defined under the bytes package so, you have to import bytes package in your program for accessing ToUpper function.
func ToUpper(slice_1 byte) byte
Here, slice_1 represents a slice of bytes which you want to convert to uppercase.
Original slice: Slice 1: geeks Slice 2: apple New Slice: Slice 1: GEEKS Slice 2: APPLE Slice 3: GEEKSFORGEEKS Slice 4: GEEKSFORGEEKS