我试图从一个更大的字符串中提取一个字符串,它得到了a:和a之间的所有东西;
当前的
Str = 'MyLongString:StringIWant;'
期望输出值
newStr = 'StringIWant'
我试图从一个更大的字符串中提取一个字符串,它得到了a:和a之间的所有东西;
当前的
Str = 'MyLongString:StringIWant;'
期望输出值
newStr = 'StringIWant'
当前回答
下面的函数获取第一个匹配项
function getStringBetween(x: string, start: string, end: string) {
const regex = new RegExp(`${start}(.*?)${end}`)
if (regex.test(x)) {
return regex.exec(x)![1]
} else return undefined
}
有测试
test("getStringBetween", () => {
const result = getStringBetween("<em> Jai Ram</em>", "<em>", "</em>")
expect(result).toEqual(" Jai Ram")
const result1 = getStringBetween(
"hare Jai Ram hare hare hare",
"hare",
"hare"
)
expect(result1).toEqual(" Jai Ram ")
})
其他回答
你可以试试这个
var mySubString = str.substring(
str.indexOf(":") + 1,
str.lastIndexOf(";")
);
你也可以用这个…
function extractText(str,delimiter){ if (str && delimiter){ var firstIndex = str.indexOf(delimiter)+1; var lastIndex = str.lastIndexOf(delimiter); str = str.substring(firstIndex,lastIndex); } return str; } var quotes = document.getElementById("quotes"); // " - represents quotation mark in HTML <div> <div> <span id="at"> My string is @between@ the "at" sign </span> <button onclick="document.getElementById('at').innerText = extractText(document.getElementById('at').innerText,'@')">Click</button> </div> <div> <span id="quotes"> My string is "between" quotes chars </span> <button onclick="document.getElementById('quotes').innerText = extractText(document.getElementById('quotes').innerText,'"')">Click</button> </div> </div>
我喜欢这个方法:
var str = 'MyLongString:StringIWant;';
var tmpStr = str.match(":(.*);");
var newStr = tmpStr[1];
//newStr now contains 'StringIWant'
var str = '[basic_salary]+100/[basic_salary]';
var arr = str.split('');
var myArr = [];
for(var i=0;i<arr.length;i++){
if(arr[i] == '['){
var a = '';
for(var j=i+1;j<arr.length;j++){
if(arr[j] == ']'){
var i = j-1;
break;
}else{
a += arr[j];
}
}
myArr.push(a);
}
var operatorsArr = ['+','-','*','/','%'];
if(operatorsArr.includes(arr[i])){
myArr.push(arr[i]);
}
var numbArr = ['0','1','2','3','4','5','6','7','8','9'];
if(numbArr.includes(arr[i])){
var a = '';
for(var j=i;j<arr.length;j++){
if(numbArr.includes(arr[j])){
a += arr[j];
}else{
var i = j-1;
break;
}
}
myArr.push(a);
}
}
myArr = ["basic_salary", "+", "100", "/", "basic_salary"]
@Babasaheb Gosavi回答是完美的,如果你有一个子字符串出现(“:”和“;”)。但一旦出现多次,就有点棘手了。
我在多个项目中提出的最佳解决方案是在一个对象中使用四个方法。
第一种方法:实际上是从两个字符串之间获得一个子字符串(但是它只会找到一个结果)。 第二种方法:删除(可能的)最近发现的结果及其前后的子字符串。 第三种方法:将上述两种方法递归地处理一个字符串。 第四种方法:将应用第三种方法并返回结果。
Code
说得够多了,让我们看看代码:
var getFromBetween = {
results:[],
string:"",
getFromBetween:function (sub1,sub2) {
if(this.string.indexOf(sub1) < 0 || this.string.indexOf(sub2) < 0) return false;
var SP = this.string.indexOf(sub1)+sub1.length;
var string1 = this.string.substr(0,SP);
var string2 = this.string.substr(SP);
var TP = string1.length + string2.indexOf(sub2);
return this.string.substring(SP,TP);
},
removeFromBetween:function (sub1,sub2) {
if(this.string.indexOf(sub1) < 0 || this.string.indexOf(sub2) < 0) return false;
var removal = sub1+this.getFromBetween(sub1,sub2)+sub2;
this.string = this.string.replace(removal,"");
},
getAllResults:function (sub1,sub2) {
// first check to see if we do have both substrings
if(this.string.indexOf(sub1) < 0 || this.string.indexOf(sub2) < 0) return;
// find one result
var result = this.getFromBetween(sub1,sub2);
// push it to the results array
this.results.push(result);
// remove the most recently found one from the string
this.removeFromBetween(sub1,sub2);
// if there's more substrings
if(this.string.indexOf(sub1) > -1 && this.string.indexOf(sub2) > -1) {
this.getAllResults(sub1,sub2);
}
else return;
},
get:function (string,sub1,sub2) {
this.results = [];
this.string = string;
this.getAllResults(sub1,sub2);
return this.results;
}
};
如何使用?
例子:
var str = 'this is the haystack {{{0}}} {{{1}}} {{{2}}} {{{3}}} {{{4}}} some text {{{5}}} end of haystack';
var result = getFromBetween.get(str,"{{{","}}}");
console.log(result);
// returns: [0,1,2,3,4,5]