let string1 = "Hello" //简单的字符串 let string2 = "Line\nNewLine" //带换行符转义序列的字符串 let string3 = @"Line\nSameLine" //使用@创建逐字字符串文字 let string4 = @"Line""with""quoutes inside" //双重仲裁,以指示@字符串内的单一仲裁 let string5 = """single "quote" is ok""" //三引号字符串文字,包括引号在内的所有符号均逐字显示 let string6 = "ab cd"// same as "ab\ncd" let string7 = "xx\ yy" //same as "xxyy", backslash at the end contunies the string without new line, leading whitespace on the next line is ignored