I have the following function:
var chr = function(X) {
return String.fromCharCode(X)
}
But I would like to use i.chr() instead of chr(i).
Q: How do I add chr() to the number prototype?
Number.prototype.chr = function() {
return String.fromCharCode(this);
}
var n = 33;
console.log(n.chr());
http://jsfiddle.net/CXWeV/
Also, as Bryan points out, the following will work:
console.log((33).chr());
console.log(Number(33).chr());
But, the following does not work:
33.chr();
EDIT: Although, as Gumbo points out, this does:
33..chr();
As well as a check if the property already exists (see Erik's answer for another way to check):
if (!Number.prototype.chr) {
Number.prototype.chr = function() {
return String.fromCharCode(this);
}
}
if (!Number.prototype.hasOwnProperty('chr')) {
Number.prototype.chr = function() {
return String.fromCharCode(this);
};
}
To use this the number must be in a variable or wrapped in parentheses. Be aware that converting a scalar number to a Number object (called boxing) has an overhead. If you are doing the conversion repeatedly on the same value, you'll want to explicitly convert it to an object first with Number().
Note that simply doing String.fromCharCode might be easier or more clear in some situations.
The normal way, really. Note the importance of surrounding the number in parentheses (or storing it in a variable), as a dot would normally indicate a decimal point:
Number.prototype.chr = function () {
return String.fromCharCode(this);
}
alert((97).chr()); // alerts "a"
I'm not sure whether this works in all browsers, but I'm assuming it does.
Interactive Example
Related
I have a string and I have to check if that string contains defined substring I need to do some work and otherwise, I should return some error.
I have the following code:
function isContains(myString) {
let subString = 'test1234';
if(myString.includes(subString)) {
// to do some work
} else {
// return some error.
}
}
but the problem is if myString = 'my-string-test1-rrr' its condition return true.
How can I get true only in case when the whole subString was included in myString?
Use indexOf() instead.
function isContains(myString) {
let subString = 'test1234';
if(myString.indexOf(subString) > -1) {
// to do some work
} else {
// return some error.
}
}
you can use regex to check if that value is present are not;
example 1
without containing the specific string
var test = 'my-string-test1-rrr';
console.log(' test --- ', test.match(/test1234/g))
example 2
contains the specific string
var test = 'my-string-test1234-rrr';
console.log(' test --- ', test.match(/test1234/g))
It is highly recommended to use includes() over indexOf() and further indexOf returns the index of the occurrence where you would prefer an immediate answer - false / true if that substring is found inside the searched string.
Your function does exactly what you are asking. I would suggest to isolate the retrieval of this function and make it purer like so, then when you have the return boolean value you could utilize it after to run whatever logic you wish. This way you keep this function pure and separate your concerns better.
I also believe it would be easier for you to debug your issue if you isolate this functions like In the example I provided.
function isContains(myString) {
let subString = 'test1234';
let isContains = false;
if(myString.includes(subString)) {
isContains = true;
} else {
isContains = false;
}
return isContains;
}
You could use it like so in a later phase in your code:
const myString = 'my-string-test1-rrr';
let shouldRunOtherLogic = isContains(myString);
if (shouldRunOtherLogic) {
// to do some work
} else {
// return some error.
}
Hope I could help, if there's anything further you may need feel free to let me know.
I'm working on some client side validation for a contact form of sorts, the website currently isn't online so server side isn't relevant.
I am trying to create a 'word filter' to catch on any abusive of obscene language before the form is 'submitted'.
Heres the code, without the obscenities...
function filterInput(str) {
var inputFilter = ['word1', 'word2', 'word3'];
var arrayLength = inputFilter.length;
if (inputFilter.indexOf(str) > - 1) {
// Word caught...
} else {
// Clear...
}
If the user were to enter 'word1', it will catch the word. If the user enters 'word1word2' or 'John is a word3', it doesn't catch it.
I originally had a for loop which worked better, but still wouldn't work without whitespace between words('word1word2').
Any input would be greatly appreciated, I've been searching but nothing quite matches my needs.
EDIT: So I too have come up with a solution, but seeing the varying ways this can be achieved I am curious as to how it works and also why a particular way is better?
Heres what I came up with...
function filterInput(str) {
var inputFilter = ['word1', 'word2', 'word3'];
var arrayLength = inputFilter.length;
for (var i = 0; i < arrayLength; i++) {
if (str.includes(inputFilter[i])) {
window.alert('Message...');
return;
}
}
}
You're looking for some rather than indexOf, since you have to do custom matching:
if (inputFilter.some(function(word) { return str.indexOf(word) != -1; })) {
// Word caught...
} else {
// Clear...
}
Or with an ES2015+ arrow function and String.prototype.includes:
if (inputFilter.some(word => str.includes(word))) {
// Word caught...
} else {
// Clear...
}
some calls the callback repeatedly until the first time it returns a truthy value. If the callback ever returns a truthy value, some returns true; otherwise, some returns false. E.g., it's asking if "some" of the entries match the predicate function. (any may have been a better term, but when adding to the built-ins, the TC39 committee have to do a lot of work to avoid conflicts with libraries and such.)
If you ever need to get back the actual entry, use find which returns the entry or undefined if not found. If you need its index, use findIndex.
Side note: Just beware that it's notoriously complicated to do this well. Beware of the Scunthorpe problem, and of course people will routinely just confuse the sequence of letters or substitute asterisks or similar to defeat filters of this sort...
you can try something like this:-
function filterInput(str) {
var badWords = ['bad', 'worst'];
var isTrue = false;
if(str) {
for (var i = 0; i < badWords.length; i++) {
isTrue = !!(str.replace(/\W|\s/g, '').toLowerCase().indexOf(badWords[i]) + 1);
if(isTrue) break;
}
}
return isTrue;
}
How change strings in javascript arrays. I want to change array codes to strings.
How change strings in javascript arrays. I want to change array codes to strings.
How to get this;
var _0x1576 = ["SayHello", "GetCount", "Message : ", "You are welcome."];
function NewObject(_0x7aa7x2) {
var _0x7aa7x3 = 0;
this.SayHello = function (_0x7aa7x4) {
_0x7aa7x3++;
alert(_0x7aa7x2 + _0x7aa7x4);
};
this.GetCount = function () {
return _0x7aa7x3
};
}
var obj = new NewObject("Message : ");
obj.SayHello("You are welcome.");
from;
var _0x1576 = ["SayHello", "GetCount", "Message : ", "You are welcome."];
function NewObject(_0x7aa7x2) {
var _0x7aa7x3 = 0;
this[_0x1576[0]] = function (_0x7aa7x4) {
_0x7aa7x3++;
alert(_0x7aa7x2 + _0x7aa7x4);
};
this[_0x1576[1]] = function () {
return _0x7aa7x3
};
}
var obj = new NewObject(_0x1576[2]);
obj.SayHello(_0x1576[3]);
EDIT: So you have some code, where all the variable names have been replaced by numbers or indices into this global array of names, and you would like to be able to read it. There is already an answer to this question, which contains links to a bunch of useful deobfuscation tools.
Your case here looks fairly trivial - it appears that you could just do a string search and replace, substituting in the array value every time it is indexed. The regexp /_0x1576\[(\d+)\]/g should find everything that accesses the variable _0x1576 with an integer index. The inner group (\d+) should give you the index with which it was found. You could use something like this to do deobfuscate your source. However, some of the names have been lost in the obfuscation process; i.e. the name of the parameter 0x7aa7x4 in the SayHello function can't be restored. You will have to read the method, understand what its' purpose is, and try to come up with a meaningful name yourself.
One question though - just how much code do you have like this? If there are only a few names in the array of strings, then #Nina Scholz's suggestion seems fairly reasonable. Just go through them one by one, in a text editor, and use the 'Find and Replace' functionality.
Just wondering if there was a way of adding in a custom jQuery method or similar to ensure all calculations are rounded to the nearest integer? E.g. for working out widths etc.
Thanks!
No, it would be impossible.
The closest you can do is change how calculations are performed in jQuery methods.
You can't change how the language itself performs arithmetic operations.
Operators can't be overriden in the JavaScript language.
Here is how you would over-ride jQuery's .width for example (this is not recommended for production code!)
$.fn.oldwidth = $.fn.width;
$.fn.width = function (elem) {
if(elem == null){ // no param, getter
return $.fn.oldwidth.call(this);
}
if (typeof elem === "string") { // 12px for example
var numPart = parseInt(elem); //get just the 12
var unitPart = elem.match(/[a-zA-Z]/g).join(""); //get the number part
return $.fn.oldwidth.call(this,Math.floor(numPart) + unitPart);
}
return $.fn.oldwidth.call(this,Math.floor(elem));
}
Working Demo
This would do:
$("#some").width("5.6em");
alert($("#some").width()); // Alerts 80 with the above code, 90 without.
if you put all calculations in a specific class you could round them globally
var Arithmetics = //class of all calc's
for(each element in arithmetics){
element = Math.round(element)
}
I don't know what kind of calculation you're trying to do, but if it's simple repetitive operations you can do a function that handle an operation and return the rounded result...
Like
function calculateSomething(operation){
// ???
return floor(result);
}
Assume you have an array:
var arrStateCityAll=['CA_Alameda','CA__Pasadena','CA_Sacramento','NY_Albany','NY_Buffalo','NY_Ithaca']
Is there an easy way using javascript and/or jQuery to filter the arrStateCityAll to get a new array (a subset of arrStateCityAll); something like this:
// return's ['CA_Alameda','CA__Pasadena','CA_Sacramento']
var arrStateCityCA=FilterArray('CA',arrStateCityAll);
Likely you want to do a regex on each item. You can do this with jQuery's grep function.
http://api.jquery.com/jQuery.grep/
You can use javascript's Array.filter.
var arrStateCityAll = ['CA_Alameda','CA__Pasadena','CA_Sacramento','NY_Albany','NY_Buffalo','NY_Ithaca']
var arrStateCityCA = arrStateCityAll.filter( function (element) {
return element.indexOf("CA_") == 0;
});
The mozilla documentation linked to above has a solution for browsers that don't implicitly support filter.
This should work.
var arrStateCityCA = [];
for (var i = 0;i<arrStateCityAll.length;i++){
if (arrStateCityAll[i].substr(0,2) == 'CA'){
arrStateCityCA.push(arrStateCityAll[i]);
}
}
You could use jQuery.grep
var arrStateCityCA =
$.grep(arrStateCityAll,function(el,i){return (el.substring(0,2)=='CA')});
Demo at jsfiddle
To implement you actual FilterArray function as shown in your post you could do
function FilterArray(state,arr){
return $.grep(arr,
function(el,i) {return (el.substring(0,2)==state)}
);
}
This makes a few assumptions.
State is always 2 chars.
State is always the first 2 chars.
And of course remember case-sensitivity (this function is case sensitive) ie 'CA' not equal to 'Ca'.
if you are going to have an undescore between your state and city name, you can split on the underscore and test against the first array value
function getSubSetByState(set,state) {
var result = [];
for(var i=0,l=set.length;i<l;++i) {
if(set[i].split('_')[0] === state) {
result.push(set[i]);
}
}
return result;
}
Use if by giving it the set of places, and then the state you are searching for.