Javascript 如何选择字符串的最后两个字符
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How to select last two characters of a string
提问by Mo.
I need to select last two characters from the variable, whether it is digit or letters.
我需要从变量中选择最后两个字符，无论是数字还是字母。
For example:
例如：
var member = "my name is maanu";
I would like to show last two letters from the string in the membervariable.
我想显示member变量中字符串的最后两个字母。
回答by
You can pass a negative index to .slice().
您可以将负索引传递给.slice().
var member = "my name is maanu";
var last2 = member.slice(-2);
alert(last2); // "nu"
回答by mattytommo
Try this, note that you don't need to specify the end index in substring.
试试这个，注意你不需要在substring.
var characters = member.substr(member.length -2);
回答by halfbit
EDIT:?2020: use string.slice(-2)as others say - see below.
编辑：？2020 年：string.slice(-2)按照其他人的说法使用- 见下文。
now 2016 just string.substr(-2)should do the trick (not substring(!))
现在 2016string.substr(-2)应该可以解决问题（不是子字符串（！））
taken from MDN
摘自 MDN
Syntax
str.substr(start[, length])Parameters
start
Location at which to begin extracting characters. If a negative number is given, it is treated as strLength + startwhere strLength is the length of the string (for example, if start is -3 it is treated as strLength - 3.) length Optional. The number of characters to extract.
句法
str.substr(start[, length])参数
开始
开始提取字符的位置。如果给出负数，则将其视为 strLength + start，其中 strLength 是字符串的长度（例如，如果 start 为 -3，则将其视为 strLength - 3。） length 可选。要提取的字符数。
EDIT?2020
编辑？2020
MDN says
MDN 说
Warning: Although String.prototype.substr(…) is not strictly deprecated (as in "removed from the Web standards"), it is considered a legacy function and should be avoided when possible. It is not part of the core JavaScript language and may be removed in the future.
警告：虽然 String.prototype.substr(...) 并未严格弃用（如“从 Web 标准中删除”），但它被视为遗留函数，应尽可能避免使用。它不是核心 JavaScript 语言的一部分，将来可能会被删除。
回答by Shrroy
The following example uses slice()with negative indexes
以下示例slice()与负索引一起使用
var str = 'my name is maanu.';
console.log(str.slice(-3)); // returns 'nu.' last two
console.log(str.slice(3, -7)); // returns 'name is'
console.log(str.slice(0, -1)); // returns 'my name is maanu'回答by thecodeparadox
You can try
你可以试试
member.substr(member.length-2);
回答by Harijs Krūtainis
If it's an integer you need a part of....
如果它是一个整数，你需要......的一部分
var result = number.toString().slice(-2);
回答by Matt
You should use substring, not jQuery, to do this.
您应该使用子字符串而不是 jQuery 来执行此操作。
Try something like this:
尝试这样的事情：
member.substring(member.length - 2, member.length)
W3Schools (not official, but occasionally helpful): http://www.w3schools.com/jsref/jsref_substring.asp
W3Schools（不是官方的，但偶尔会有帮助）：http: //www.w3schools.com/jsref/jsref_substring.asp
Adding MDN link as requested by commenter: https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/substring
根据评论者的要求添加 MDN 链接：https: //developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/substring
回答by Biju s
var member = "my name is maanu";
var answer=member.substring(0,member.length - 2);
var answer=member.substring(0,member.length - 2);
alert(answer);
