Javascript 如何获取字符串的前三个字符
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Javascript How to get first three characters of a string
提问by Phon Soyang
This may duplicate with previous topics but I can't find what I really need.
这可能与以前的主题重复，但我找不到我真正需要的东西。
I want to get a first three characters of a string. For example:
我想获取字符串的前三个字符。例如：
var str = '012123';
console.info(str.substring(0,3)); //012
I want the output of this string '012' but I don't want to use subString or something similar to it because I need to use the original string for appending more characters '45'. With substring it will output 01245 but what I need is 01212345.
我想要这个字符串 '012' 的输出，但我不想使用 subString 或类似的东西，因为我需要使用原始字符串来附加更多字符 '45'。使用子字符串它将输出 01245 但我需要的是 01212345。
回答by Alexander Nied
var str = '012123';
var strFirstThree = str.substring(0,3);
console.log(str); //shows '012123'
console.log(strFirstThree); // shows '012'Now you have access to both.
现在您可以访问两者。
回答by Flimm
slice(begin, end)works on strings, as well as arrays. It returns a string representing the substring of the original string, from beginto end(endnot included) where beginand endrepresent the index of characters in that string.
slice(begin, end)适用于字符串和数组。它返回一个表示原始字符串的子字符串的字符串，从begin到end（end不包括）其中begin和end表示该字符串中字符的索引。
const string = "0123456789";
console.log(string.slice(0, 2)); // "01"
console.log(string.slice(0, 8)); // "01234567"
console.log(string.slice(3, 7)); // "3456"