How to find a number in a string using JavaScript

Question

Suppose I have a string like -  you can enter maximum 500 choices   I need to extract 500 from the string   The main problem is the String may vary like  you can enter maximum 12500 choices   So how to get the integer part

User · Answer

Use a regular expression   var r     d    var s    you can enter maximum 500 choices   alert  s match r      The expression  d  means  one or more digits   Regular expressions by default are greedy meaning they ll grab as much as they can  Also  this   var r     d      is equivalent to   var r   new RegExp   d       See the details for the RegExp object   The above will grab the first group of digits  You can loop through and find all matches too   var r     d  g  var s    you can enter 333 maximum 500 choices   var m  while   m   r exec s      null      alert m 0        The g  global  flag is key for this loop to work

User · Answer

I like  jesterjunk answer   however  a number is not always just digits  Consider those valid numbers   123 5  123 567 789  12233234 E12   So I just updated the regular expression   var regex      d     e E      g   var string    you can enter maximum 5 123 6 choices   var matches   string match regex       creates array from matches  document write matches     5 123 6

User · Answer

var str    you can enter maximum 500 choices   str replace    0-9  g       console log str       500

User · Answer

I thought I d add my take on this since I m only interested in the first integer I boiled it down to this  let errorStringWithNumbers    quot error  404  not found  quot           let errorNumber   parseInt errorStringWithNumbers toString   match   d  g  0      toString   is added only if you get the  quot string quot  from an fetch error  If not  then you can remove it from the line

User · Answer

x000D   x000D  var regex     d  g  x000D  var string    you can enter maximum 500 choices   x000D  var matches   string match regex       creates array from matches x000D   x000D  document write matches   x000D   x000D   x000D    References    nbsp   nbsp  http   www regular-expressions info javascript html   nbsp   nbsp  https   developer mozilla org en-US docs Web JavaScript Reference Global Objects RegExp

User · Answer

x000D   x000D  var regex     d  g  x000D  var string    you can enter 30 -20  maximum 500 choices   x000D  var matches   string match regex       creates array from matches x000D   x000D  document write matches   x000D   x000D   x000D

User · Answer

You can also try this      x000D   x000D  var string    border-radius 10px 20px 30px 40px   x000D  var numbers   string match   d  g  map Number   x000D  console log numbers  x000D   x000D   x000D

User · Answer

stringValue can be anything in which present any number  const stringValue    last 15 days        d  g is regex which is used for matching number in string    match helps to find result according to regex from string and return match value  const result   stringValue match   d  g    console log result         output will be 15   If You want to learn more about regex here are some links   https   www w3schools com jsref jsref obj regexp asp  https   developer mozilla org en-US docs Web JavaScript Guide Regular Expressions  https   www tutorialspoint com javascript javascript regexp object htm

[javascript] How to find a number in a string using JavaScript?

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