If you are in a situation where you need to remove last few (one or two, or even three or so on) characters from a 
Simply use this function to remove any number of desired characters from your string (variable)
substr($your-variable,0,-1);
In the above function $your-variable is the variable that you want to be trimmed off and from which you want to exclude those alphabets or characters using php. 0 defines the first character from the left for the new variable and -1 defines the last (second last one in this case)
Example PHP remove last 3 characters from a string
So if you want to remove 3 characters from the end of php string variable, simply do this:
$my-variable = “Mr. Nabeel is greatest”;
$my-new-variable = substr($my-variable,0,-3);
echo $my-new-variable;
Upon echo, it will show : Mr. Nabeel is great instead of Mr. Nabeel is greatest.
Similarly if we use this php function as:
$my-variable = “Mr. Nabeel is greatest”;
$my-new-variable = substr($my-variable,4,-3);
echo $my-new-variable;
Now it will show only Nabeel is great trimming off four characters from the beginning and three from the end of the sentence string variable using php builtin substr function.