I have a string:
var example = 'sorted-by-' + number;
Where number variable can be any positive integer. I don't know how to reverse this process, not knowing how many digits this number has. I want to get from example string a number at the end.
var outputNumber = example.substring(10);
This is the simple solution because example string always start with 'sorted-by-'.
let num = + string.substr(10);
You can use String#replace function to replace sorted-by- to empty string and after that convert left part to a number:
var example = 'sorted-by-' + 125;
var num = +example.replace('sorted-by-', '');
console.log(num);
You can split string at - and get last element using pop().
var example = 'sorted-by-' + 100.99
var n = +(example.split('-').pop())
console.log(n)
You can also use regex for this.
var number = 245246245;
var example = 'sorted-by-' + number;
var res = example.match(/^sorted-by-(\d+)/);
console.log(+res[1]);
Related
I know that if either one of my operands is a string, it should prefer string concatenation, but I get an integer.
var number = 134324;
var num_str = number + "";
console.log(num_str);
No it should not return string .. as you are printing it in console it looks like integer but try using
var number = 134324;
var num_str = number + "";
console.log(num_str);
typeof(num_str);
It will display that your answer is string ... :) hope you satisfied ..
You can use toString() method.
num_str = number.toString()
I am aware of name.charCodeAt(0). I am having issued with the following code, so I want a solution for below.
var number= 2;
var t = number.charCodeAt(0);
console.log(t);
The answer needs to be in ASCII. I am getting the log as 2 and not as ASCII value 50. What can be the issue?
ASCII is a way of representing String data. You need to first convert your Number to String;
Remember also that String can have arbitrary length so you'll need to iterate over every character.
var x = 2,
str_x = '' + x,
chrs = Array.prototype.map.call(str_x, function (e) {return e.charCodeAt(0);});
chrs; // [50]
Finally, JavaScript works with UTF-16/UCS-2 and not plain ASCII. Luckily the values for digits are the same in both so you don't have to do any further transformation here.
You have to cast a number to a string first to use .charCodeAt to get the numerical character code.
var number = 2;
var t = String( number ).charCodeAt( 0 );
console.log( t ); // 50
Just convert the number to String and call the method on it.
var number = 2;
var numberInString = number.toString();
var code = numberInString.charCodeAt(0);
console.log(code);
I have a number that I need to pull from my html:
<span>123,456.78</span>
How can I convert this string into a number that I can do math on?
var numberString = $('span').text();
var realNumber = Number(numberString); //returns NaN
A jQuery-only solution would be okay.
parseInt() or parseFloat() would just about do it.
var number = parseFloat($('span').text());
after checking and seeing this doesn't work...
try
var number =
$('span').text().replace(/([^0-9\.])/g,"");
var number = parseFloat($('span').text().replace(/([^0-9\\.])/g,""));
I'm not sure what realNumber does, but here's how I'd convert that string into a number:
var numberString = $('span').text();
var amount = + numberString.replace(/,/g, '');
This removes the commas, then uses the + unary operator to convert the string to a number. In your example, the result is the number 123456.78.
updated
var numberString = $('span').text();
var number = Number(numberString.replace(/[^0-9\.]+/g,""));
I have a string like:
text-345-3535
The numbers can change.
How can I get the two numbers from it and store that into two variables?
var str = "text-345-3535"
var arr = str.split(/-/g).slice(1);
Try it out: http://jsfiddle.net/BZgUt/
This will give you an array with the last two number sets.
If you want them in separate variables add this.
var first = arr[0];
var second = arr[1];
Try it out: http://jsfiddle.net/BZgUt/1/
EDIT:
Just for fun, here's another way.
Try it out: http://jsfiddle.net/BZgUt/2/
var str = "text-345-3535",first,second;
str.replace(/(\d+)-(\d+)$/,function(str,p1,p2) {first = p1;second = p2});
var m = "text-345-3535".match(/.*?-(\d+)-(\d+)/);
m[1] will hold "345" and m[2] will have "3535"
If you're not accustomed to regular expressions, #patrick dw's answer is probably better for you, but this should work as well:
var strSource = "text-123-4567";
var rxNumbers = /\b(\d{3})-(\d{4})\b/
var arrMatches = rxNumbers.exec(strSource);
var strFirstCluster, strSecondCluster;
if (arrMatches) {
strFirstCluster = arrMatches[1];
strSecondCluster = arrMatches[2];
}
This will extract the numbers if it is exactly three digits followed by a dash followed by four digits. The expression can be modified in many ways to retrieve exactly the string you are after.
Try this,
var text = "text-123-4567";
if(text.match(/-([0-9]+)-([0-9]+)/)) {
var x = Text.match(/([0-9]+)-([0-9]+)/);
alert(x[0]);
alert(x[1]);
alert(x[2]);
}
Thanks.
Another way to do this (using String tokenizer).
int idx=0; int tokenCount;
String words[]=new String [500];
String message="text-345-3535";
StringTokenizer st=new StringTokenizer(message,"-");
tokenCount=st.countTokens();
System.out.println("Number of tokens = " + tokenCount);
while (st.hasMoreTokens()) // is there stuff to get?
{words[idx]=st.nextToken(); idx++;}
for (idx=0;idx<tokenCount; idx++)
{System.out.println(words[idx]);}
}
output
words[0] =>text
words[1] => 345
words[2] => 3535
I need to extract a single variable number from a string. The string always looks like this:
javascript:change(5);
with the variable being 5.
How can I isolate it? Many thanks in advance.
Here is one way, assuming the number is always surrounded by parentheses:
var str = 'javascript:change(5);';
var lastBit = str.split('(')[1];
var num = lastBit.split(')')[0];
Use regular expressions:-
var test = "javascript:change(5);"
var number = new RegExp("\\d+", "g")
var match = test.match(number);
alert(match);
A simple RegExp can solve this one:
var inputString = 'javascript:change(5);';
var results = /javascript:change\((\d+)\)/.exec(inputString);
if (results)
{
alert(results[1]); // 5
}
Using the javascript:change part in the match as well ensures that if the string isn't in the proper format, you wont get a value from the matches.
var str = 'javascript:change(5);', result = str.match(/\((\d+)\)/);
if ( result ) {
alert( result[1] )
}