Use substr() to remove the last character of a string

When making statistical charts, you need to separate the data with "," when extracting it. However, when I use a loop to accumulate strings, it is inevitable that there will be an extra "," in the end. For example, I took out 1,2,3,4,5, but I need to delete the comma at the end of the string to get 1,2,3,4,5. Solution: Using php’s substr method, Syntax: string substr(string string, int start, int [length]); Parameter 1: original string; Parameter 2: starting position of cutting; Parameter 3: intercepted length; Use it like this: $newstr = substr($str,0,strlen($str)-1); Cut from the beginning to the penultimate digit, thus removing the last ",".