使用JavaScript获取字符串中的第一个整数 [英] Get the first integers in a string with JavaScript

问题描述

我在循环中有一个字符串，对于每个循环，它都填充了如下所示的文本：

I have a string in a loop and for every loop, it is filled with texts the looks like this:

"123 hello everybody 4"
"4567 stuff is fun 67"
"12368 more stuff"

我只想检索字符串中文本的第一个数字，当然，我不知道长度。

I only want to retrieve the first numbers up to the text in the string and I, of course, do not know the length.

提前致谢！

推荐答案

如果数字位于字符串的开头：

If the number is at the start of the string:

("123 hello everybody 4").replace(/(^\d+)(.+$)/i,'$1'); //=> '123'

如果它在字符串中的某个位置：

If it's somewhere in the string:

(" hello 123 everybody 4").replace( /(^.+)(\w\d+\w)(.+$)/i,'$2'); //=> '123'

以及字符之间的数字：

("hello123everybody 4").replace( /(^.+\D)(\d+)(\D.+$)/i,'$2'); //=> '123'

[附录]

匹配字符串中所有数字的正则表达式：

A regular expression to match all numbers in a string:

"4567 stuff is fun4you 67".match(/^\d+|\d+\b|\d+(?=\w)/g); //=> ["4567", "4", "67"]

您可以将生成的数组映射到数字数组：

You can map the resulting array to an array of Numbers:

"4567 stuff is fun4you 67"
  .match(/^\d+|\d+\b|\d+(?=\w)/g)
  .map(function (v) {return +v;}); //=> [4567, 4, 67]

包括花车：

"4567 stuff is fun4you 2.12 67"
  .match(/\d+\.\d+|\d+\b|\d+(?=\w)/g)
  .map(function (v) {return +v;}); //=> [4567, 4, 2.12, 67]

如果存在字符串不包含任何内容的可能性数字，使用：

If the possibility exists that the string doesn't contain any number, use:

( "stuff is fun"
   .match(/\d+\.\d+|\d+\b|\d+(?=\w)/g) || [] )
   .map(function (v) {return +v;}); //=> []

因此，检索字符串的起始或结束编号 4567东西是fun4you 2.12 67

So, to retrieve the start or end numbers of the string 4567 stuff is fun4you 2.12 67"

// start number
var startingNumber = ( "4567 stuff is fun4you 2.12 67"
  .match(/\d+\.\d+|\d+\b|\d+(?=\w)/g) || [] )
  .map(function (v) {return +v;}).shift(); //=> 4567

// end number
var endingNumber = ( "4567 stuff is fun4you 2.12 67"
  .match(/\d+\.\d+|\d+\b|\d+(?=\w)/g) || [] )
  .map(function (v) {return +v;}).pop(); //=> 67

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