Javascript 在Javascript中获取字符串中每个单词的第一个字母
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Get first letter of each word in a string, in Javascript
提问by Gerben Jacobs
How would you go around to collect the first letter of each word in a string, as in to receive an abbreviation?
您将如何收集字符串中每个单词的第一个字母，例如接收缩写？
String: "Java Script Object Notation"
Wanted result: "JSON"
回答by BotNet
I think what you're looking for is the acronym of a supplied string.
我认为您正在寻找的是所提供字符串的首字母缩写词。
var str = "Java Script Object Notation";
var matches = str.match(/\b(\w)/g); // ['J','S','O','N']
var acronym = matches.join(''); // JSON
console.log(acronym)Note:this will fail for hyphenated/apostrophe'd words Help-me I'm Dieingwill be HmImD. If that's not what you want, the split on space, grab first letterapproach might be what you want.
注：这将失败的连字符/ apostrophe'd话Help-me I'm Dieing会HmImD。如果这不是你想要的，空间分割，抓住第一个字母的方法可能是你想要的。
Here's a quick example of that:
这是一个简单的例子：
let str = "Java Script Object Notation";
let acronym = str.split(/\s/).reduce((response,word)=> response+=word.slice(0,1),'')
console.log(acronym);回答by hugomg
I think you can do this with
我认为你可以做到这一点
'Aa Bb'.match(/\b\w/g).join('')
Explanation:Obtain all /gthe alphanumeric characters \wthat occur after a non-alphanumeric character (i.e: after a word boundary \b), put them on an array with .match()and join everything in a single string .join('')
说明：获取出现在非字母数字字符之后的所有/g字母\w数字字符（即：在单词边界之后\b），将它们放在一个数组中，.match()并将所有内容连接到一个字符串中.join('')
Depending on what you want to do you can also consider simply selecting all the uppercase characters:
根据您要执行的操作，您还可以考虑简单地选择所有大写字符：
'JavaScript Object Notation'.match(/[A-Z]/g).join('')
回答by Almis
Easiest way without regex
没有正则表达式的最简单方法
var abbr = "Java Script Object Notation".split(' ').map(function(item){return item[0]}).join('');
回答by Aaron Taddiken
This is made very simple with ES6
这在ES6 中变得非常简单
string.split(' ').map(i => i.charAt(0)) //Inherit case of each letter
string.split(' ').map(i => i.charAt(0)).toUpperCase() //Uppercase each letter
string.split(' ').map(i => i.charAt(0)).toLowerCase() //lowercase each letter
This ONLY works with spaces or whatever is defined in the .split(' ')method
这仅适用于空格或.split(' ')方法中定义的任何内容
ie, .split(', ').split('; '), etc..
即.split(', ').split('; ')，等等。
回答by tomersss2
@BotNet flaw: i think i solved it after excruciating 3 days of regular expressions tutorials:
@BotNet 缺陷：我想我在折磨了 3 天的正则表达式教程后解决了它：
==> I'm a an animal
==> 我是一只动物
(used to catch m of I'm) because of the word boundary, it seems to work for me that way.
（用于捕捉我的 m）由于词边界，它似乎对我有用。
/(\s|^)([a-z])/gi
回答by Darryl Hebbes
To add to the great examples, you could do it like this in ES6
要添加到很棒的示例中，您可以在 ES6 中这样做
const x = "Java Script Object Notation".split(' ').map(x => x[0]).join('');
console.log(x); // JSON
and this works too but please ignore it, I went a bit nuts here :-)
这也有效，但请忽略它，我在这里有点疯狂:-)
const [j,s,o,n] = "Java Script Object Notation".split(' ').map(x => x[0]);
console.log(`${j}${s}${o}${n}`);
回答by Ben Sarah Golightly
Using map(from functional programming)
使用map（来自函数式编程）
'use strict';
function acronym(words)
{
if (!words) { return ''; }
var first_letter = function(x){ if (x) { return x[0]; } else { return ''; }};
return words.split(' ').map(first_letter).join('');
}
回答by ipr101
Try -
尝试 -
var text = '';
var arr = "Java Script Object Notation".split(' ');
for(i=0;i<arr.length;i++) {
text += arr[i].substr(0,1)
}
alert(text);
Demo - http://jsfiddle.net/r2maQ/
回答by Fatma Nabilla
Alternative 1:
备选方案 1：
you can also use this regex to return an array of the first letter of every word
您还可以使用此正则表达式返回每个单词的第一个字母的数组
/(?<=(\s|^))[a-z]/gi
(?<=(\s|^))is called positive lookbehindwhich make sure the element in our search pattern is preceded by (\s|^).
(?<=(\s|^))被调用positive lookbehind以确保我们搜索模式中的元素以(\s|^).
so, for your case:
所以，对于你的情况：
// in case the input is lowercase & there's a word with apostrophe
const toAbbr = (str) => {
return str.match(/(?<=(\s|^))[a-z]/gi)
.join('')
.toUpperCase();
};
toAbbr("java script object notation"); //result JSON
(by the way, there are also negative lookbehind, positive lookahead, negative lookahead, if you want to learn more)
（顺便说一句，如果你想了解更多，还有negative lookbehind, positive lookahead, negative lookahead）
Alternative 2:
备选方案 2：
match all the words and use replace()method to replace them with the first letter of each word and ignore the space (the method will not mutate your original string)
匹配所有单词并使用replace()方法将它们替换为每个单词的第一个字母并忽略空格（该方法不会改变您的原始字符串）
// in case the input is lowercase & there's a word with apostrophe
const toAbbr = (str) => {
return str.replace(/(\S+)(\s*)/gi, (match, p1, p2) => p1[0].toUpperCase());
};
toAbbr("java script object notation"); //result JSON
// word = not space = \S+ = p1 (p1 is the first pattern)
// space = \s* = p2 (p2 is the second pattern)
回答by Vadim Gremyachev
Yet another option using reducefunction:
使用reduce函数的另一个选项：
var value = "Java Script Object Notation";
var result = value.split(' ').reduce(function(previous, current){
return {v : previous.v + current[0]};
},{v:""});
$("#output").text(result.v);<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<pre id="output"/>