I'm trying to insert some whitespace in a string if the string conforms to a certain format. Specifically, if the string consists of only numbers, and is exactly five characters in length, whitespace should be added between the third and fourth numbers.
Here's my test case:
function codeAddress() {
var num_regex = /^\d+$/,
input = $("#distributor-search").val(),
address = (input.match(num_regex) && input.length == 5) ? input.split('').splice(3, 0 , ' ').join() : input ;
console.log('The address is: ' + address);
return false;
}
For some reason, chaining .split(), .splice() and .join() seems to not return anything. Where am I going wrong?
split() returns an array, splice() returns the array with the removed elements and join() returns the joined array like they should.
Looks like everything goes wrong at splice(). Instead of giving the remainders, you get the removed items.
My test:
var input = '123,789';
var output = input.split(',').splice(1, 0, '456').join(',');
console.log(output); // outputs nothing, because `splice(1, 0, '456')` doesn't remove any values
You could solve this by making a prototype that uses splice's functionality, like so:
Array.prototype.isplice = function() {
var tmp = this;
Array.prototype.splice.apply(tmp, Array.prototype.isplice.arguments);
return tmp;
};
var output = input.split(',').isplice(1, 0, '456').join(',');
console.log(output); // outputs ["123", "456", "789"] as expected
As others have explained, your function didn't work because .splice() returns the removed elements, instead of the resulting array.
Try using this regex, instead:
/^(\d\d\d)(\d\d)$/
It will only match a string if it's 5 digits long, it won't modify other strings.
Examples:
var s = '123456'.replace(/^(\d\d\d)(\d\d)$/, '$1 $2');
// "123456"
var s = '1234'.replace(/^(\d\d\d)(\d\d)$/, '$1 $2');
// "1234"
var s = '12345'.replace(/^(\d\d\d)(\d\d)$/, '$1 $2');
// "123 45"
So, in your case:
address = $("#distributor-search").val().replace(/^(\d\d\d)(\d\d)$/, '$1 $2');
Why not just use the regex itself?
var num_regex = /^(\d\d\d)(\d\d)$/,
input = $("#distributor-search").val(),
address = input.match(num_regex);
if (address) address = address[1] + ' ' + address[2];
That regex matches a five-digit string and groups the first three and last two digits together. If the test string matches, then the .match() function returns an array with the two groups in positions 1 and 2 (position 0 being the entire match).
You can't concatenate splice with join in your case:
splice(3, 0 , ' ').join()
remember that splice returns a new array containing the removed items, not the result array.
Related
I'm working with a string where I need to extract the first n characters up to where numbers begin. What would be the best way to do this as sometimes the string starts with a number: 7EUSA8889er898 I would need to extract 7EUSA But other string examples would be SWFX74849948, I would need to extract SWFX from that string.
Not sure how to do this with regex my limited knowledge is blocking me at this point:
^(\w{4}) that just gets me the first four characters but I don't really have a stopping point as sometimes the string could be somelongstring292894830982 which would require me to get somelongstring
Using \w will match a word character which includes characters and digits and an underscore.
You could match an optional digit [0-9]? from the start of the string ^and then match 1+ times A-Za-z
^[0-9]?[A-Za-z]+
Regex demo
const regex = /^[0-9]?[A-Za-z]+/;
[
"7EUSA8889er898",
"somelongstring292894830982",
"SWFX74849948"
].forEach(s => console.log(s.match(regex)[0]));
Can use this regex code:
(^\d+?[a-zA-Z]+)|(^\d+|[a-zA-Z]+)
I try with exmaple and good worked:
1- somelongstring292894830982 -> somelongstring
2- 7sdfsdf5456 -> 7sdfsdf
3- 875werwer54556 -> 875werwer
If you want to create function where the RegExp is parametrized by n parameter, this would be
function getStr(str,n) {
var pattern = "\\d?\\w{0,"+n+"}";
var reg = new RegExp(pattern);
var result = reg.exec(str);
if(result[0]) return result[0].substr(0,n);
}
There are answers to this but here is another way to do it.
var string1 = '7EUSA8889er898';
var string2 = 'SWFX74849948';
var Extract = function (args) {
var C = args.split(''); // Split string in array
var NI = []; // Store indexes of all numbers
// Loop through list -> if char is a number add its index
C.map(function (I) { return /^\d+$/.test(I) === true ? NI.push(C.indexOf(I)) : ''; });
// Get the items between the first and second occurence of a number
return C.slice(NI[0] === 0 ? NI[0] + 1 : 0, NI[1]).join('');
};
console.log(Extract(string1));
console.log(Extract(string2));
Output
EUSA
SWFX7
Since it's hard to tell what you are trying to match, I'd go with a general regex
^\d?\D+(?=\d)
How can I output an array as a scentence except the (1) item? Let's say the content of the array is: ["!report","Jay","This","is","the","reason"];
I tried this to output the items after the (1): (args.slice(1));however the output now is: "This,is,the,reason", how could I make it output as a normal scentence?
If you don't want to use built in methods, you can append each word
in the array starting at index 1 (second item).
// List of words
var words = ["!report","Jay","This","is","the","reason"];
// Empty string
var sentence = "";
// Loop through array starting at index 1 (second item)
for (let i = 1; i < words.length; i++) {
// Keep appending the words to sentence string
sentence = sentence + words[i] + " ";
}
// Print the sentence as a whole
console.log(sentence);
Or using built in functions:
// Array of strings
var array = ["!report","Jay","This","is","the","reason"];
// Cut off the first element, words is still an array though
var words = array.slice(1)
// Join each element into a string with spaces in between
var sentence = words.join(" ")
// Print as full sentence
console.log(sentence)
Output:
"Jay This is the reason"
You could slice from the second element and join the array.
console.log(["!report","Jay","This","is","the","reason"].slice(2).join(' '));
.slice() returns a new array, so when you access it as a whole, you often see a comma separated list of the array values.
But, .slice() along with .join() does the trick. .join() allows you to "join" all the array values as a single string. If you pass an argument to .join(), that argument will be used as a separator.
You can then just concatenate a period (.) to the end of the string.
console.log(["!report","Jay","This","is","the","reason"].slice(1).join(" ") + ".");
The output you desire is not very clear (do you want to remove only the first item or also the second). However the methods are the same:
you can use destructuring assignment syntax if you're es6 compliant
const arr = [a,b,...c] = ["!report","Jay","This","is","the","reason"];
let sentence = c.join(" ");
// or
let sentence2 = c.toString().replace(/,/g," ");
console.log (sentence," - ",sentence2);
or simply replace with regex and a correct pattern
const arr = ["!report","Jay","This","is","the","reason"];
let sentence = arr.toString().replace(/^[A-z! ]+?,[A-z ]+?,/,"").replace(/,/g," ");
// or
let sentence2 = arr.toString().replace(/^[A-z! ]+?,/,"").replace(/,/g," ");
console.log (sentence," - ",sentence2);
Here it is, check fiddle comments for code explanation.
var a = ["!report","Jay","This","is","the","reason"];
//removes first element from array and implodes array with spaces
var sentence = a.slice(1).join(" ");
console.log(sentence);
When I utilise the slice method like so:
"Hello".slice(0,-1);
The result I get will be "Hell". Then if I run through that again using the same code, I will get "Hel".
Is there a way that I can extract and store into a variable the actual character that was sliced off, in this case "H" or on the second run "e", and not just the remainder of the string?
You could just use a second .slice() on the original string.
For example, where "Hello".slice(0,-1); returns all but the last character, "Hello".slice(-1) returns only the last character.
var input = "Hello";
var removed = input.slice(-1); // "o"
var remaining = input.slice(0, -1); // "Hell"
I don't think there's a more generic solution than that, because .slice() also lets you extract the middle of a string, in which case you'd need two extra calls to get the two parts being removed.
Demo:
var input = "Hello";
var allRemoved = [];
var removed;
while (input != "") {
allRemoved.push(removed = input.slice(-1));
input = input.slice(0, -1);
console.log("'" + removed + "' removed, leaving '" + input + "'");
}
console.log("Removed: " + allRemoved.join(", "));
Alternatively, if you only care about removing characters one at a time, you could forget about .slice() and instead convert the string to an array and use .shift() or .pop() to remove the character at the beginning or end respectively:
var input = "Hello";
var inArr = input.split("");
while (inArr.length > 0) {
console.log(inArr.pop());
}
This might not be the most efficient way to do this but you can turn yout string as an array with .split, then use .splice to remove certain elements ( letters ) and store them as a variable. Finally you turn your variable of removed letters back to a string using .join
let name = 'David'
let arrayname = name.split('')
let chosenLetters = arrayname.splice(0,2)
let finalLetters = chosenLetters.join('')
console.log(finalLetters) //should output Da
For split and join I recommend you leave the argument as (''). For .splice you can find in the docs for js how to select specific letters. In my example I am saying "Start at index 0 and cut the first 2 elements". Splice has many other ways to select an index so I recommend you read the docs.
In one line of code it can be generalized to :
let name = 'David'
let finalLetters = name.split('').splice(0,2).join('')
console.log(finalLetters) //should output Da
I'm trying to change a huge string into the array of chars. In other languages there is .toCharArray(). I've used split to take dots, commas an spaces from the string and make string array, but I get only separated words and don't know how to make from them a char array. or how to add another regular expression to separate word? my main goal is something else, but I need this one first. thanks
var str = " If you don't pass anything, you'll get an array containing only the original string, rather than an array containing each character."
str = str.toLowerCase();
str = str.split(/[ ,.]+/);
You can use String#replace with regex and String#split.
arrChar = str.replace(/[', ]/g,"").split('');
Demo:
var str = " If you don't pass anything, you'll get an array containing only the original string, rather than an array containing each character.";
var arrChar = str.replace(/[', ]/g,"").split('');
document.body.innerHTML = '<pre>' + JSON.stringify(arrChar, 0, 4) + '</pre>';
Add character in [] which you want to remove from string.
This will do:
var strAr = str.replace(/ /g,' ').toLowerCase().split("")
First you have to replace the , and . then you can split it:
var str = " If you don't pass anything, you'll get an array containing only the original string, rather than an array containing each character."
var strarr = str.replace(/[\s,.]+/g, "").split("");
document.querySelector('pre').innerHTML = JSON.stringify(strarr, 0, 4)
<pre></pre>
var charArray[];
for(var i = 0; i < str.length; i++) {
charArray.push(str.charAt(i));
}
Alternatively, you can simply use:
var charArray = str.split("");
I'm trying to change a huge string into the array of chars.
This will do
str = str.toLowerCase().split("");
The split() method is used to split a string into an array of
substrings, and returns the new array.
Tip: If an empty string ("") is used as the separator, the string is
split between each character.
Note: The split() method does not change the original string.
Please read the link:
http://www.w3schools.com/jsref/jsref_split.asp
You may do it like this
var coolString,
charArray,
charArrayWithoutSpecials,
output;
coolString = "If you don't pass anything, you'll get an array containing only the original string, rather than an array containing each character.";
// does the magic, uses string as an array to slice
charArray = Array.prototype.slice.call(coolString);
// let's do this w/o specials
charArrayWithoutSpecials = Array.prototype.slice.call(coolString.replace(/[', ]/g,""))
// printing it here
output = "<b>With special chars:</b> " + JSON.stringify(charArray);
output += "<br/><br/>";
output += "<b>With special chars:</b> " + JSON.stringify(charArrayWithoutSpecials)
document.write(output);
another way would be
[].slice.call(coolString)
I guess this is what you are looking for. Ignoring all symbols and spaces and adding all characters in to an array with lower case.
var str = " If you don't pass anything, you'll get an array containing only the original string, rather than an array containing each character."
str = str.replace(/\W/g, '').toLowerCase().split("");
alert(str);
I only want to remove the first 100 words and keep whats remaining from the string.
The code I have below does the exact opposite:
var short_description = description.split(' ').slice(0,100).join(' ');
Remove the first argument:
var short_description = description.split(' ').slice(100).join(' ');
Using slice(x, y) will give you elements from x to y, but using slice(x) will give you elements from x to the end of the array. (note: this will return the empty string if the description has less than 100 words.)
Here is some documentation.
You could also use a regex:
var short_description = description.replace(/^([^ ]+ ){100}/, '');
Here is an explanation of the regex:
^ beginning of string
( start a group
[^ ] any character that is not a space
+ one or more times
then a space
) end the group. now the group contains a word and a space.
{100} 100 times
Then replace those 100 words with nothing. (note: if the description is less than 100 words, this regex will just return the description unchanged.)
//hii i am getting result using this function
var inputString = "This is file placed on Desktop"
inputString = removeNWords(inputString, 2)
console.log(inputString);
function removeNWords(input,n) {
var newString = input.replace(/\s+/g,' ').trim();
var x = newString.split(" ")
return x.slice(n,x.length).join(" ")
}
The reason this is doing the opposite, is that slice returns the selected elements (in this case, the first one hundred) and returns them in it's own array. To get all of the elements after one hundred, you would have to do something like description.slice(100) to get the split array properly, and then your own join to merge back the array.
var short_description = description.split(' ').slice(100).join(' ');