Extract a number from a string using JavaScript
The number from a string in javascript can be extracted into an array of numbers by using the match method. This function takes a regular expression as an argument and extracts the number from the string. Regular expression for extracting a number is (/(\d+)/).
Example 1: This example uses match() function to extract number from string.
html
<!DOCTYPE html><html><head> <title> Extract number from string </title></head><body > <div align="center" style="background-color: green;"> <h1>GeeksforGeeks</h1> <p>String is "jhkj7682834"</p> <p id="GFG"> Click the button to extract number </p> <input type="button" value="click " onclick="myGeeks()"> </div> <script> function myGeeks() { var str = "jhkj7682834"; var matches = str.match(/(\d+)/); if (matches) { document.getElementById('GFG').innerHTML = matches[0]; } } </script></body></html> |
Output:
- Before Clicking the button:
- After Clicking the button:
Example 2: This example uses match() function to extract number from string.
html
<!DOCTYPE html><html><head> <title> Extract number from string </title></head><body> <div align="center" style="background-color: green;"> <h1>GeeksforGeeks</h1> <p>String is "foo35bar5jhkj88"</p> <h3> The string contains 3 numbers. So the numbers are stored in an array and print together </h3> <p id="GFG"> Click the button to extract number </p><br> <h3 id="Geeks"></h3> <input type="button" value="Click Here!" onclick="myGeeks()"> </div> <script> function myGeeks() { var str = "foo35bar5jhkj88"; matches = str.match(/\d+/g); var i=0 document.getElementById('GFG').innerHTML = matches[0] + matches[1] + matches[2]; document.getElementById("Geeks").innerHTML = "Where 35 is the first, 5 is the second" + " and 88 is the third number" } </script></body></html> |
Output:
- Before Clicking the button:
- After Clicking the button:
Example#3 : This example uses reduce method to extract all the number from string.
HTML
<!DOCTYPE html><html><head> <title> Extract number from string </title></head><body > <div align="center" style="background-color: green;"> <h1>GeeksforGeeks</h1> <p>String is "jhkj7682834"</p> <p id="GFG"> Click the button to extract number </p> <input type="button" value="click " onclick="myGeeks()"> </div> <script> function myGeeks() { var str = "jhkj7682834"; var c = '0123456789' function check(x) { return c.includes(x) ? true : false; } var matches = [...str].reduce((x, y) => check(y) ? x+y : x, '') if (matches) { document.getElementById('GFG').innerHTML = matches; } } </script></body></html> |
Output:
- Before clicking Button:
reduce () function
- After clicking Button:
reduce()
JavaScript is best known for web page development but it is also used in a variety of non-browser environments. You can learn JavaScript from the ground up by following this JavaScript Tutorial and JavaScript Examples.
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