我有一个字符串:
var string = "aaaaaa<br />† bbbb<br />‡ cccc"
我想用分隔符<br />拆分这个字符串，后面跟着一个特殊字符。
要做到这一点，我使用这个:
string.split(/<br \/>&#?[a-zA-Z0-9]+;/g);
我得到了我需要的东西，只是我丢失了分隔符。 示例如下:http://jsfiddle.net/JwrZ6/1/
如何保留分隔符?
当前回答
我遇到了类似但略有不同的问题。无论如何，这里有三种不同场景的示例，用于说明在何处保存分隔符。
"1、2、3".split("、") == ["1", "2", "3"]
"1、2、3".split(/(、)/g) == ["1", "、", "2", "、", "3"]
"1、2、3".split(/(?=、)/g) == ["1", "、2", "、3"]
"1、2、3".split(/(?!、)/g) == ["1、", "2、", "3"]
"1、2、3".split(/(.*?、)/g) == ["", "1、", "", "2、", "3"]
警告:第四个只适用于拆分单个字符。ConnorsFan提供了一个替代方案:
// Split a path, but keep the slashes that follow directories
var str = 'Animation/rawr/javascript.js';
var tokens = str.match(/[^\/]+\/?|\//g);
其他回答
扩展函数将字符串与子字符串或RegEx分开，分隔符根据第二个参数放在前面或后面。
String.prototype.splitKeep = function (splitter, ahead) {
var self = this;
var result = [];
if (splitter != '') {
var matches = [];
// Getting mached value and its index
var replaceName = splitter instanceof RegExp ? "replace" : "replaceAll";
var r = self[replaceName](splitter, function (m, i, e) {
matches.push({ value: m, index: i });
return getSubst(m);
});
// Finds split substrings
var lastIndex = 0;
for (var i = 0; i < matches.length; i++) {
var m = matches[i];
var nextIndex = ahead == true ? m.index : m.index + m.value.length;
if (nextIndex != lastIndex) {
var part = self.substring(lastIndex, nextIndex);
result.push(part);
lastIndex = nextIndex;
}
};
if (lastIndex < self.length) {
var part = self.substring(lastIndex, self.length);
result.push(part);
};
// Substitution of matched string
function getSubst(value) {
var substChar = value[0] == '0' ? '1' : '0';
var subst = '';
for (var i = 0; i < value.length; i++) {
subst += substChar;
}
return subst;
};
}
else {
result.add(self);
};
return result;
};
测试:
test('splitKeep', function () {
// String
deepEqual("1231451".splitKeep('1'), ["1", "231", "451"]);
deepEqual("123145".splitKeep('1', true), ["123", "145"]);
deepEqual("1231451".splitKeep('1', true), ["123", "145", "1"]);
deepEqual("hello man how are you!".splitKeep(' '), ["hello ", "man ", "how ", "are ", "you!"]);
deepEqual("hello man how are you!".splitKeep(' ', true), ["hello", " man", " how", " are", " you!"]);
// Regex
deepEqual("mhellommhellommmhello".splitKeep(/m+/g), ["m", "hellomm", "hellommm", "hello"]);
deepEqual("mhellommhellommmhello".splitKeep(/m+/g, true), ["mhello", "mmhello", "mmmhello"]);
});
我还想到了这个解。不需要正则表达式，非常易读。
Const STR = "你好，世界，今天多么美好的一天balbla" const separatorIndex = str.indexOf("great") const parsedString = str.slice(separatorIndex) console.log (parsedString)
如果将分隔符括在parantheses中，它将是返回数组的一部分。
string.split(/(<br \/>&#?[a-zA-Z0-9]+);/g);
// returns ["aaaaaa", "<br />†", "bbbb", "<br />‡", "cccc"]
根据你想保留的部分来改变你匹配的子组
string.split(/(<br \/>)&#?[a-zA-Z0-9]+;/g);
// returns ["aaaaaa", "<br />", "bbbb", "<br />", "cccc"]
您可以通过忽略字母的大小写来改进表达式 string.split (/ () & # ? [a-z0-9] +, / gi);
你可以这样匹配预定义的组:\d =[0-9]和\w = [a-zA-Z0-9_]。这意味着表达式可以是这样的。
string.split(/<br \/>(&#?[a-z\d]+;)/gi);
JavaScriptKit上有一个很好的正则表达式参考。
回答它这里也JavaScript分割正则表达式保持分隔符
在正则表达式中使用(?=pattern)前向模式 例子
var string = '500x500-11*90~1+1';
string = string.replace(/(?=[$-/:-?{-~!"^_`\[\]])/gi, ",");
string = string.split(",");
这将得到以下结果。
[ '500x500', '-11', '*90', '~1', '+1' ]
还可以直接拆分吗
string = string.split(/(?=[$-/:-?{-~!"^_`\[\]])/gi);
给出相同的结果
[ '500x500', '-11', '*90', '~1', '+1' ]
Most of the existing answers predate the introduction of lookbehind assertions in JavaScript in 2018. You didn't specify how you wanted the delimiters to be included in the result. One typical use case would be sentences delimited by punctuation ([.?!]), where one would want the delimiters to be included at the ends of the resulting strings. This corresponds to the fourth case in the accepted answer, but as noted there, that solution only works for single characters. Arbitrary strings with the delimiters appended at the end can be formed with a lookbehind assertion:
'It is. Is it? It is!'.split(/(?<=[.?!])/)
/* [ 'It is.', ' Is it?', ' It is!' ] */
