switch语句
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 | 错误代码：<!DOCTYPE HTML><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>switch</title><script type="text/JavaScript"> function b() { var myweek=prompt("今天星期几？","1"); switch(myweek) { case 1: case 2: document.write("学习理论知识"); break; case 3: case 4: document.write("到企业去实践"); break; case 5: document.write("总结经验"); break; case 6: case 7: document.write("休息娱乐"); break; default:alert("不查就不查"); } }</script></head><body> <input name="button" type="submit" value="查看今日任务" onclick="b()" /></body></html>正确代码：<!DOCTYPE HTML><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>switch</title><script type="text/JavaScript"> function b() { var myweek=prompt("今天星期几？","1"); switch(myweek) { case '1': case '2': document.write("学习理论知识"); break; case '3': case '4': document.write("到企业去实践"); break; case '5': document.write("总结经验"); break; case '6': case '7': document.write("休息娱乐"); break; default:alert("不查就不查"); } }</script></head><body> <input name="button" type="submit" value="查看今日任务" onclick="b()" /></body></html>下面代码就是比上面代码case值那里多了单引号的区别，请问case值那里什么时候要单引号什么时候不要？why？ |
