Question

这里是我的代码，其中包含我尝试做的详细信息：

    var str = "Hello m|sss sss|mmm ss"
//Now i separate them by "|"
    var str1 = str.split('|');

 //Now i want to get the first word of every split-ed sting parts:

        for (var i=0;i<codelines.length;i++)
        {
    //What to do here to get the first word of every spilt
        }

那我该怎么办：\ 我想得到的是firstword [0]将给出“Hello”，firstword [1]将给出“sss”而firstword [2]将给出“mmm”

Answer 1

再次用空格拆分：

var firstWords = [];
for (var i=0;i<codelines.length;i++)
{
  var words = codelines[i].split(" ");
  firstWords.push(words[0]);
}

或者使用String.prototype.substr()（可能更快）：

var firstWords = [];
for (var i=0;i<codelines.length;i++)
{
  var codeLine = codelines[i];
  var firstWord = codeLine.substr(0, codeLine.indexOf(" "));
  firstWords.push(firstWord);
}

Answer 2

使用正则表达式

＆＃13;

var totalWords = "foo love bar very much.";

var firstWord = totalWords.replace(/ .*/,'');

$('body').append(firstWord);

＆＃13;

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

＆＃13;

Answer 3

我用这个：

takeWhile

Answer 4

如何使用underscorejs

str = "There are so many places on earth that I want to go, i just dont have time. :("
firstWord = _.first( str.split(" ") )

Answer 5

var str = "Hello m|sss sss|mmm ss"
//Now i separate them by "|"
var str1 = str.split('|');

//Now i want to get the first word of every split-ed sting parts:

for (var i=0;i<str1.length;i++)
{
    //What to do here to get the first word :)
    var firstWord = str1[i].split(' ')[0];
    alert(firstWord);
}

Answer 6

对先前答案的改进（处理多行或标签字符串）：

String.prototype.firstWord = function(){return this.replace(/\s.*/,'')}

或使用search和substr：

String.prototype.firstWord = function(){let sp=this.search(/\s/);return sp<0?this:this.substr(0,sp)}

或没有正则表达式：

String.prototype.firstWord = function(){
  let sps=[this.indexOf(' '),this.indexOf('\u000A'),this.indexOf('\u0009')].
   filter((e)=>e!==-1);
  return sps.length? this.substr(0,Math.min(...sps)) : this;
}

示例：

＆＃13;

String.prototype.firstWord = function(){return this.replace(/\s.*/,'')}
console.log(`linebreak
example 1`.firstWord()); // -> linebreak
console.log('space example 2'.firstWord()); // -> singleline
console.log('tab	example 3'.firstWord()); // -> tab

＆＃13;

Answer 7

要获取字符串的第一个单词，您可以这样做：

let myStr = "Hello World"
let firstWord = myStr.split(" ")[0]

Answer 8

此代码应该为您提供第一个单词，

var str = "Hello m|sss sss|mmm ss"
//Now i separate them by "|"
var str1 = str.split('|');

 //Now i want to get the first word of every split-ed sting parts:

 for (var i=0;i<str1.length;i++)
 {
     //What to do here to get the first word :(
     var words = str1[i].split(" ");
     console.log(words[0]);
 }

Answer 9

我很惊讶没有提到这种方法："Some string".split(' ').shift()

直接回答问题：

let firstWords = []
let str = "Hello m|sss sss|mmm ss";
const codeLines = str.split("|");

for (var i = 0; i < codeLines.length; i++) {
  const first = codeLines[i].split(' ').shift()
  firstWords.push(first)
}

Answer 10

const getFirstWord = string => {
    const firstWord = [];
    for (let i = 0; i < string.length; i += 1) {
        if (string[i] === ' ') break;
        firstWord.push(string[i]);
    }
    return firstWord.join('');
};
console.log(getFirstWord('Hello World'));

或简化它：

const getFirstWord = string => {
    const words = string.split(' ');
    return words[0];
};
console.log(getFirstWord('Hello World'));

Answer 11

最简单的方法之一就是这样

var totalWords = "my name is rahul.";
var firstWord = totalWords.replace(/ .*/, '');
alert(firstWord);
console.log(firstWord);

Answer 12

在现代JS中，这是简化的，您可以编写如下代码：

const firstWords = str =>
  str .split (/\|/) .map (s => s .split (/\s+/) [0])

const str = "Hello m|sss sss|mmm ss"

console .log (firstWords (str))

我们首先在|上分割字符串，然后在结果数组中的任何空格上分割每个字符串，仅保留第一个。

获取字符串的第一个字

12 个答案: