我如何分裂一个字符串与多个分隔符在JavaScript?
我试图拆分逗号和空格,但AFAIK JavaScript的split()函数只支持一个分隔符。
我如何分裂一个字符串与多个分隔符在JavaScript?
我试图拆分逗号和空格,但AFAIK JavaScript的split()函数只支持一个分隔符。
当前回答
我不知道RegEx的性能如何,但这里有另一个RegEx的替代方案,它利用了本机HashSet,并在O(max(str)中工作。长度,delimeter.length))
var multiSplit = function(str,delimiter){
if (!(delimiter instanceof Array))
return str.split(delimiter);
if (!delimiter || delimiter.length == 0)
return [str];
var hashSet = new Set(delimiter);
if (hashSet.has(""))
return str.split("");
var lastIndex = 0;
var result = [];
for(var i = 0;i<str.length;i++){
if (hashSet.has(str[i])){
result.push(str.substring(lastIndex,i));
lastIndex = i+1;
}
}
result.push(str.substring(lastIndex));
return result;
}
multiSplit('1,2,3.4.5.6 7 8 9',[',','.',' ']);
// Output: ["1", "2", "3", "4", "5", "6", "7", "8", "9"]
multiSplit('1,2,3.4.5.6 7 8 9',' ');
// Output: ["1,2,3.4.5.6", "7", "8", "9"]
其他回答
我将为这样的函数提供一个经典的实现。代码可以在几乎所有版本的JavaScript中运行,并且在某种程度上是最优的。
它不使用正则表达式,这很难维护 它没有使用JavaScript的新特性 它不使用需要更多计算机内存的多次.split() .join()调用
只是纯代码:
var text = "Create a function, that will return an array (of string), with the words inside the text";
println(getWords(text));
function getWords(text)
{
let startWord = -1;
let ar = [];
for(let i = 0; i <= text.length; i++)
{
let c = i < text.length ? text[i] : " ";
if (!isSeparator(c) && startWord < 0)
{
startWord = i;
}
if (isSeparator(c) && startWord >= 0)
{
let word = text.substring(startWord, i);
ar.push(word);
startWord = -1;
}
}
return ar;
}
function isSeparator(c)
{
var separators = [" ", "\t", "\n", "\r", ",", ";", ".", "!", "?", "(", ")"];
return separators.includes(c);
}
你可以看到代码在playground中运行: https://codeguppy.com/code.html?IJI0E4OGnkyTZnoszAzf
传入一个regexp作为参数:
js> "Hello awesome, world!".split(/[\s,]+/)
Hello,awesome,world!
编辑补充:
你可以通过选择数组的长度减去1来获得最后一个元素:
>>> bits = "Hello awesome, world!".split(/[\s,]+/)
["Hello", "awesome", "world!"]
>>> bit = bits[bits.length - 1]
"world!"
... 如果模式不匹配:
>>> bits = "Hello awesome, world!".split(/foo/)
["Hello awesome, world!"]
>>> bits[bits.length - 1]
"Hello awesome, world!"
从@stephen-sweriduk解决方案开始(这对我来说更有趣!),我对它进行了轻微的修改,使其更加通用和可重用:
/**
* Adapted from: http://stackoverflow.com/questions/650022/how-do-i-split-a-string-with-multiple-separators-in-javascript
*/
var StringUtils = {
/**
* Flatten a list of strings
* http://rosettacode.org/wiki/Flatten_a_list
*/
flatten : function(arr) {
var self=this;
return arr.reduce(function(acc, val) {
return acc.concat(val.constructor === Array ? self.flatten(val) : val);
},[]);
},
/**
* Recursively Traverse a list and apply a function to each item
* @param list array
* @param expression Expression to use in func
* @param func function of (item,expression) to apply expression to item
*
*/
traverseListFunc : function(list, expression, index, func) {
var self=this;
if(list[index]) {
if((list.constructor !== String) && (list[index].constructor === String))
(list[index] != func(list[index], expression)) ? list[index] = func(list[index], expression) : null;
(list[index].constructor === Array) ? self.traverseListFunc(list[index], expression, 0, func) : null;
(list.constructor === Array) ? self.traverseListFunc(list, expression, index+1, func) : null;
}
},
/**
* Recursively map function to string
* @param string
* @param expression Expression to apply to func
* @param function of (item, expressions[i])
*/
mapFuncToString : function(string, expressions, func) {
var self=this;
var list = [string];
for(var i=0, len=expressions.length; i<len; i++) {
self.traverseListFunc(list, expressions[i], 0, func);
}
return self.flatten(list);
},
/**
* Split a string
* @param splitters Array of characters to apply the split
*/
splitString : function(string, splitters) {
return this.mapFuncToString(string, splitters, function(item, expression) {
return item.split(expression);
})
},
}
然后
var stringToSplit = "people and_other/things";
var splitList = [" ", "_", "/"];
var splittedString=StringUtils.splitString(stringToSplit, splitList);
console.log(splitList, stringToSplit, splittedString);
归还原物的:
[ ' ', '_', '/' ] 'people and_other/things' [ 'people', 'and', 'other', 'things' ]
您可以将所有想要单独或共同用作分隔符的字符合并到一个正则表达式中,并将它们传递给split函数。例如,你可以这样写:
console.log( "dasdnk asd, (naks) :d skldma".split(/[ \(,\)]+/) );
输出将是:
["dasdnk", "asd", "naks", ":d", "skldma"]
我不知道RegEx的性能如何,但这里有另一个RegEx的替代方案,它利用了本机HashSet,并在O(max(str)中工作。长度,delimeter.length))
var multiSplit = function(str,delimiter){
if (!(delimiter instanceof Array))
return str.split(delimiter);
if (!delimiter || delimiter.length == 0)
return [str];
var hashSet = new Set(delimiter);
if (hashSet.has(""))
return str.split("");
var lastIndex = 0;
var result = [];
for(var i = 0;i<str.length;i++){
if (hashSet.has(str[i])){
result.push(str.substring(lastIndex,i));
lastIndex = i+1;
}
}
result.push(str.substring(lastIndex));
return result;
}
multiSplit('1,2,3.4.5.6 7 8 9',[',','.',' ']);
// Output: ["1", "2", "3", "4", "5", "6", "7", "8", "9"]
multiSplit('1,2,3.4.5.6 7 8 9',' ');
// Output: ["1,2,3.4.5.6", "7", "8", "9"]