检查最后一个字符是否为点 (.)

Question

I need to check if the last character of an input ( type="number" ) value is a dot!

Tried these, but it doesn't work:

let amount = $("#amount").val();
let last_char = amount.slice(-1);
if(last_char == ".")
{
    return;
}

Also tried amount[amount.length-1] and charAt()

PS Input type is type="number"

Edit:

None of the answers work: https://jsfiddle.net/dne37hao/

Answer 1

 const string = 'Is this a question.'; console.log(string.endsWith('.'));

Answer 2

You can achieve this using different ways but with different performance,

1. Using bracket notation:

var str = "Test";
var lastLetter = str[str.length - 1];

But it's not recommended to use brackets.

2. charAt[index]:

var lastLetter = str.charAt(str.length - 1)

This is readable and fastest among others. It is most recommended way.

3. substring:

str.substring(str.length - 1);

4. slice:

if(str.slice(-1)=== '.'){
return true
}

It's slightly faster than substring.The most efficient one

With ES6:

You can use str.endsWith("t");

Answer 3

You can try this:

let amount = $("#amount").val();
if(amount[amount.length-1] === "."){
   return true;
}