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problem Description : Allow 1 to 6 English characters or numbers, press OK to end
valid equivalence classes : Lengths: 1 to 6
Character: a-z,a-z,0-9
invalid equivalence class : Length: 0,7
Characters: English/numeric characters, control characters, punctuation
Can be drawn:
| Valid equivalence classes | Invalid equivalence class |
| Length:1-6 | Length:. -0&&7-.. |
| Char:a-z&&a-z&&0-9 | Char:others |
The test cases and results used are:
| Test Cases | Test results |
| 0 | Effective |
| A | Effective |
| Z | Effective |
| 9 | Effective |
| AA90 | Effective |
| Ababab | Effective |
| 9a2b7c | Effective |
| Mmmmmm | Effective |
| bbbbbb | Effective |
| 12 | Effective |
| 123 | Effective |
| 1234 | Effective |
| 12345 | Effective |
| 123456 | Effective |
| 1234567 | Invalid |
| Abcdefg | Invalid |
| Akbugg | Effective |
| 、 | Invalid |
| **** | Invalid |
| Kghggggg | Invalid |
| 1k2m3 | Effective |
| Invalid |
The key code for the programming test implementation is:
12 34<script type= "Text/javascript" >5 functionequaltest () {6 varName = document.getElementById (' name '). Value;7 if(Name = =NULL)8 {9Window.alert ("User name cannot be empty");Ten } One Else A { - varnlen=name.length; -reg=/^[a-za-z0-9_]+$/; the - if(nlen<1| | Nlen>6) - { -Window.alert ("illegal") + } - Else if(!reg.test (name)) + { AWindow.alert ("illegal"); at } - Else return; - } - } -</script> - in -<body> to<input type= "text" id= "name"/><br/> +<input type= "button" onclick= "Equaltest ()" value= "OK"/> -</body> the *PS: In regular expressions, if a character is given directly, it is precisely matched. You can match a number to match \d \w a letter or a number.
To make a more accurate match, you can use a [] representation range, such as:
[0-9a-zA-Z\_]Can match a number, letter, or underscore;
[0-9a-zA-Z\_]+Can match a string of at least one number, letter, or underscore, for example, and ‘a100‘ ‘0_Z‘ ‘Py3000‘ so on;
[a-zA-Z\_][0-9a-zA-Z\_]*It can be matched by a letter or underscore, followed by a string consisting of a number, letter, or underscore, which is a valid Python variable;
[a-zA-Z\_][0-9a-zA-Z\_]{0, 19}More precisely limit the length of a variable to 1-20 characters (1 characters before + 19 characters later).
Validity verification of user name input in--web development of equivalence class test
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