词法分析器即词法分析程序又称为扫描器，其功能在于依次扫视字符串形式源程序中的各个字符，逐个识别出其中的单词，并将其转换为内部编码形式的单词符号串作确为输出-Lexical analyzer that lexical analysis program, also known as scanner, its function is to sweep a string followed by the various characters in the form of the source program one by one to identify one of the words and convert them to symbols within the encoded form of the word strings to make do for the Output