Stacey Fontenot

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&gt;&gt; ^([0-9][0-9]?).[0,5]$|^(99<wbr />.5)$<br />
That regex also matches the following:<br />
<br />
<b>99a5</b><br />
The dot &quot;matches anything except newline&quot;. &nbsp;Thus, you can put a lot of things instead on the &quot;a&quot; (9995 also matches!). &nbsp;So, if you want a literal dot, you need to escape it with a backslash OR enclose it in square brackets.<br />
<br />
<b>99,0</b><br />
the characters in the square brackets are literal characters. So, &quot;[0,5]&quot; means &quot;zero OR comma OR five&quot;. &nbsp;So you need to either omit the comma or use the alternation operator =&gt; (0|5)<br />
<br />
Try the following regex:<br />

<pre><code id="code-20-42766379-1">^(\d{1,2})\.(0|5)$</code></pre>
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>> ^([0-9][0-9]?).[0,5]$|^(99.5)$
That regex also matches the following:

99a5
The dot "matches anything except newline".  Thus, you can put a lot of things instead on the "a" (9995 also matches!).  So, if you want a literal dot, you need to escape it with a backslash OR enclose it in square brackets.

99,0
the characters in the square brackets are literal characters. So, "[0,5]" means "zero OR comma OR five".  So you need to either omit the comma or use the alternation operator => (0|5)

Try the following regex:


^(\d{1,2})\.(0|5)$

Web Craftsman & Consultant

David S.

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I have an input field that requires a user to enter time in a decimal form of hours + minutes. I need an html validation regex that will force a user to only enter the decimal 0 or 5. For example, user can enter the following valid numbers: (10.0; 10.5; 11.0; 3.5; 2.0) and so on. Invalid numbers:( 10.1; 10.2; 10.4; 3.2; 4.4;7.7). I just need to ensure user enters .0 or .5 decimal &nbsp;no greater than 99.5, and great than 0.
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I have an input field that requires a user to enter time in a decimal form of hours + minutes. I need an html validation regex that will force a user to only enter the decimal 0 or 5. For example, user can enter the following valid numbers: (10.0; 10.5; 11.0; 3.5; 2.0) and so on. Invalid numbers:( 10.1; 10.2; 10.4; 3.2; 4.4;7.7). I just need to ensure user enters .0 or .5 decimal  no greater than 99.5, and great than 0.

Validation of Input Field for Decimal Places

A regular expression ("regex") is a sequence of characters that define a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. "find and replace"-like operations. Regular expression processors are found in several search engines, search and replace dialogs of several word processors and text editors, and in the command lines of text processing utilities, such as sed and AWK. Many programming languages provide regular expression capabilities, some built-in, for example Perl, JavaScript, Ruby, AWK, and Tcl, and others via a standard library, for example .NET languages, Java, Python and C++ (since C++11). Most other languages offer regular expressions via a library.

Regular Expressions

HTML (HyperText Markup Language) is the main markup language for creating web pages and other information to be displayed in a web browser, providing both the structure and content for what is sent from a web server through the use of tags. The current implementation of the HTML specification is HTML5.

HTML

JavaScript is a dynamic, object-based language commonly used for client-side scripting in web browsers. Recently, server side JavaScript frameworks have also emerged. JavaScript runs on nearly every operating system and  in almost every mainstream web browser.