string specification operand

例句：

1. 1.The program uses a string specifier to determine the length of the string.
   该程序使用一个字符串规格符来确定字符串的长度。
2. 2.The operand is the value that gets assigned to the variable.
   操作数是赋值给变量的值。
3. 3. The programmer needs to know the string specifier and operand to modify the string.
   程序员需要知道字符串规格符和操作数来修改字符串。