《VF程序设计 实习教程与习题集》辽大版 单元实习内容答案.docVIP

《VF程序设计 实习教程与习题集》辽大版1~13单元实习内容答案 VF programming practice tutorial and problem sets, 1~13 unit internship content answer 2009-05-07 10:55 (| classification: default classification) Practice tutorial first units Visual FoxPro basic operations (reference answer) 1. use the method of assignment to determine whether the following string is a valid memory variable name: 1) execute the assignment command: X1=3, or STORE 3, TO, X1 The system does not show any error, and knows that X1 is the legal memory variable name. Similarly, X_1 is also a valid memory variable name, and the rest is illegal. 2) use the above method to judge: Variable, variable X, variable 1, variable _1 is legal memory variable name, and the rest is illegal. 2. calculate and display the results of each of the following questions: 1) use function: Command: mod (987654321123456789) Display: 9 Utilization operation: Command: 987654321%, 123456789 Display: 9 2) command: X=5.1249 Min (2^X, X^2) Display: 26.2646 3) command: C1=AB C2=SPACE (2) C3=str (3.14,5,2) A1=C1+C2+C3 A2=trim (C1+C2-C3) LEN (A1), LEN (A2) Display: 97 4) command: C1= SPACE (2) C2= ABC C3=SPACE (3) A1=C1+C2+C3 A2=trim (C1+C2+C3) A3=ltrim (C1+C2+C3) A4=alltrim (C1+C2+C3) Len (A1, A2, A2, A3, A4 Len (A1, A2, A2, A3, A4) Len (A1), len (A2), len (A3), len (A4) Display: 8563 5) command: A=Microcomputer SUBSTR (A, 1,2) +SUBSTR (A, 9,2) Display: Microcomputer 6) command: date () +10000 Display: 07/11/32 (relating to the date of the day) 7) command: date () -{^1997-7-1} Display: 2794 (relating to the date of the day) 8) .T. II..T. 3. use the following functions through examples: 1) MOD (10, -3) =-2 MOD (-10, 3) =2 MOD (-10, -3) =1 2) ROUND (12345.6789,1) =12345.7 ROUND (12345.6789,0) = 12346 ROUND (12345.6789, -1) =12350 ROUND (12345.6789, -2) =12300 3) the case where the second, third parameters of the function STR are exact: (revised in May 29, 2005) STR (3.1415926,4,1) = 3.1 STR (3.1415926,4) = 3 STR (3.1415926) = 3 Practice tutorial second unit