1、Format：[n]FC[+][-][width]
By default, if the value being formatted uses fewer characters than specified by the width parameter, IDL pads the value with whitespace characters on the left to create a string of the specified width. For example, the following IDL statement
For numeric format codes, if the first digit of the width parameter is a zero, IDL will pad the value with zeroes rather than blanks. For example:
