- JavaScript Basics
- JavaScript Tutorial
- JavaScript: where to write
- JavaScript: how to display
- JavaScript: keywords
- JavaScript: comments
- JavaScript: variables
- JavaScript: operators
- JavaScript: data types
- JavaScript Conditional Statements
- JavaScript: if-else
- JavaScript: switch
- JavaScript: for loop
- JavaScript: while loop
- JavaScript: do-while loop
- JavaScript: break and continue
- JavaScript Popup Boxes
- JavaScript: alert box
- JavaScript: confirm box
- JavaScript: prompt box
- JavaScript Popular Topics
- JavaScript: functions
- JavaScript: innerHTML
- JavaScript: getElementById()
- JavaScript: getElementsByClassName()
- JavaScript: getElementsByName()
- JavaScript: getElementsByTagName()
- JavaScript: querySelector()
- JavaScript: querySelectorAll()
- JavaScript: document.write()
- JavaScript: console.log()
- JavaScript: boolean
- JavaScript: events
- JavaScript: Math object
- JavaScript: Math.random()
- JavaScript: Number()
- JavaScript: parseInt()
- JavaScript: parseFloat()
- JavaScript Arrays
- JavaScript: array
- JavaScript: find length of array
- JavaScript: add element at beginning
- JavaScript: add element at end
- JavaScript: remove first element
- JavaScript: remove last element
- JavaScript: get first index
- JavaScript: get last index
- JavaScript: reverse an array
- JavaScript: sort an array
- JavaScript: concatenate arrays
- JavaScript: join()
- JavaScript: toString()
- JavaScript: from()
- JavaScript: check if value exists
- JavaScript: check if array
- JavaScript: slice an array
- JavaScript: splice()
- JavaScript: find()
- JavaScript: findIndex()
- JavaScript: entries()
- JavaScript: every()
- JavaScript: fill()
- JavaScript: filter()
- JavaScript: forEach()
- JavaScript: map()
- JavaScript Strings
- JavaScript: string
- JavaScript: length of string
- JavaScript: convert to lowercase
- JavaScript: convert to uppercase
- JavaScript: string concatenation
- JavaScript: search()
- JavaScript: indexOf()
- JavaScript: search() vs. indexOf()
- JavaScript: match()
- JavaScript: match() vs. search()
- JavaScript: replace()
- JavaScript: toString()
- JavaScript: String()
- JavaScript: includes()
- JavaScript: substr()
- JavaScript: slice string
- JavaScript: charAt()
- JavaScript: repeat()
- JavaScript: split()
- JavaScript: charCodeAt()
- JavaScript: fromCharCode()
- JavaScript: startsWith()
- JavaScript: endsWith()
- JavaScript: trim()
- JavaScript: lastIndexOf()
- JavaScript Date and Time
- JavaScript: date and time
- JavaScript: Date()
- JavaScript: getFullYear()
- JavaScript: getMonth()
- JavaScript: getDate()
- JavaScript: getDay()
- JavaScript: getHours()
- JavaScript: getMinutes()
- JavaScript: getSeconds()
- JavaScript: getMilliseconds()
- JavaScript: getTime()
- JavaScript: getUTCFullYear()
- JavaScript: getUTCMonth()
- JavaScript: getUTCDate()
- JavaScript: getUTCDay()
- JavaScript: getUTCHours()
- JavaScript: getUTCMinutes()
- JavaScript: getUTCSeconds()
- JavaScript: getUTCMilliseconds()
- JavaScript: toDateString()
- JavaScript: toLocaleDateString()
- JavaScript: toLocaleTimeString()
- JavaScript: toLocaleString()
- JavaScript: toUTCString()
- JavaScript: getTimezoneOffset()
- JavaScript: toISOString()
- JavaScript Regular Expression
- JavaScript: regular expression
- JavaScript: RegEx . (dot)
- JavaScript: RegEx \w and \W
- JavaScript: RegEx \d and \D
- JavaScript: RegEx \s and \S
- JavaScript: RegEx \b and \B
- JavaScript: RegEx \0
- JavaScript: RegEx \n
- JavaScript: RegEx \xxx
- JavaScript: RegEx \xdd
- JavaScript: RegEx quantifiers
- JavaScript: RegEx test()
- JavaScript: RegEx lastIndex
- JavaScript: RegEx source
- JavaScript Programs
- JavaScript Programs
JavaScript \xdd Metacharacter | Find Character using HexaDecimal Number
The JavaScript \xdd metacharacter is used when we need to match a character using its hexadecimal number (in the form xdd), while working with JavaScript regular expressions. For example:
<!DOCTYPE html>
<html>
<body>
<p id="xyz"></p>
<script>
let myString = "JavaScript is Fun.";
let pattern = /\x75/;
document.getElementById("xyz").innerHTML = myString.search(pattern);
</script>
</body>
</html>The code begins by declaring an empty HTML paragraph element with the ID "xyz".
A string variable "myString" is declared and assigned the value "JavaScript is Fun." in the script section.
The following line declares a regular expression variable "pattern" with the pattern /\x75/. The pattern \x75 corresponds to the Unicode character at position 0x75 (in hexadecimal), which is equivalent to the letter "u".
The string "myString" is then searched using the search() method for the first occurrence of the pattern specified in the "pattern" variable. The position of the first match is returned by the search() method, or -1 if no match is found.
Finally, the position of the first match is set as the content of the HTML paragraph element with the ID "xyz" using the document object's innerHTML property. Because the pattern matches the character "u" in the string "JavaScript is Fun.", the output is the position of the first occurrence of "u," which is 4.
Since the hexadecimal value 75 refers to u. And the index of u in the string is 15. Therefore, the program has produced 15 as output.
Note: The search() function is used to search a substring (value) in a string using a regular expression.
Now, before closing the discussion on the "\xdd" metacharacter while working with the JavaScript RegEx, I'm willing to include one more example that might help you better understand the topic. So here is an example:
<!DOCTYPE html>
<html>
<body>
<p id="output"></p>
<script>
// Declare a string variable containing a hexadecimal escape sequence
let myString = "\x41\x42\x43";
// Set the content of the HTML paragraph element with ID "output" to the value of myString
document.getElementById("output").innerHTML = myString;
</script>
</body>
</html>ABC
The "\xdd" metacharacter is used in this example to represent a hexadecimal escape sequence in a string. The escape sequence "\x41\x42\x43" in the string "myString" represents the ASCII characters "A", "B", and "C" in hexadecimal notation.
« Previous Tutorial Next Tutorial »