Analysis of the differences between js substr and java substring and C substring

js substr(start[,length]) means to take length strings from the start position

js substring(start,end) represents a string from start to end, including start but not end

java sbustring(start,end) represents the string from start to end, including the start position it includes the end position

c# Substring(start[,length]) represents the fetching of length strings from the start position