Regex not matching properly - javascript

Ive been working on this regex for days now and I cant get it figured out. It either passes everything I put in there or it kicks everything out and I cannot seem to make it function. Admittedly I am new to doing this complex of stuff with Javascript so It may be that you realy cant do this.
I want to check onkeypress what was entered into the input and then validate it to x, y, or z. Then from there send it on about its way to do other neat stuff.
So the question is what the heck am I not understanding about RegExp?
Here is a FIDDLE for it.
function val() {
var gradeIn = document.querySelectorAll("#letGrade input[type=text]");
var checkGrade = new RegExp(/[xyz]/gi);
for (var i = 0; i < gradeIn.length; i++) {
if (!checkGrade.test(gradeIn.value)) {
alert ("This must be X, Y, or Z");
return false;
} else {
return true;
}
}
};
EDIT/UPDATE:
I was trying to do this on keypress and validate each text input individualy however this was realy kinda squishy in the grand scheme of things and not working out exactly correct. I decided to validate all text inputs onsubmit and have everything go all at once. Updated code is below.
function calcGPA() {
var grades = document.querySelectorAll("#letGrade input[type=text]");
var contacts = document.querySelectorAll("#conHours input[type=text]");
var gVals = [];
var cVals = [];
var failGrade = "The Letter Grade input may only be A, B, C, D or F";
var failHours = "The Contact Hours input may only be 1, 2, 3, 4 or 5";
var checkGrade = /^[ABCDF]/;
var checkhours = /^[12345]/;
for (var i = 0; i < grades.length; i++) {
if (!checkGrade.test(grades[i].value)) {
alert(failGrade);
return false;
}
if (!checkhours.test(contacts[i].value)) {
alert(failHours);
return false;
}
gVals.push(grades[i].value);
cVals.push(contacts[i].value);
}
//Other cool stuff happens here
};
Now to just finish the conversion piece for the letters to numbers and the math piece. Thank you for your help on this!


The problem's not only with your regular expression.
if (!checkGrade.test(gradeIn[i].value)) {
You weren't checking each grade. Now if you want it to only be those characters, you have to extend the regular expression a bit. Also, there's no point calling new RegExp if you're using native syntax.
var checkGrade = /^[xyz]+$/;
That means that you're OK with the fields being like "xxyyz" or "zzy". If it should just be one character, that'd be
var checkGrade = /^[xyz]$/;

Related

Force first letter uppercase in input field

I'm practicing some JavaScript and would love to hear your thoughts regarding this script I wrote. I've managed to make this work. The script makes the first letter of the input value uppercase using the script below. I'm just wondering if this is a good method of doing this/if my steps are in good order just to get better
love to hear more ways of doing so, even making an option to eliminate the caps-lock via keyboard thanks,
// my input var
var strInput =document.querySelector("#inputText > input");
// my function and eventlistener
strInput.addEventListener('input',function() {
//upper case first letter with concatenate string input
var outputString = strInput.value.charAt(0).toUpperCase() + strInput.value.slice(1);
this.value = outputString;
});

As in the comments requested
Here is an example to bind the event to ALL text-inputs (except <textarea> and contenteditable="true")
var txtInputs = document.querySelectorAll("input[type='text'");
//just a simple validation if its not null, undefined or empty
if (txtInputs && txtInputs.length > 0) {
for (var i = 0; i < txtInputs.length; i++) {
var txtInput = txtInputs[i];
txtInput.addEventListener('input', function() {
var outputString = this.value.charAt(0).toUpperCase() + this.value.slice(1);
});
}

Passing a string through an array looking for regEx

I'm currently making a chatbox in JQuery. I've been using indexOf but I think it might be more efficient to use regExp.
my current code is
function ai(message){
if (username.length<3){
username = message;
send_message("Nice, to meet you " + username + ", how are you doing?");
}
if(message.indexOf("how are you?")>=0) {
send_message("I'm feeling great!");
}
if(message.indexOf("weather")>=0 ){
send_message("In England it is shitty");
}
var n = message.search(/\b(cat|cats|kitten|feline)\b/i);
if (n !== -1) {
send_message("i hate cats");
}
else {
for (i=0; i <= botChat.length; i++) {
var re = new RegExp (botChat[i][0], 'i');
if (re.test(message)) {
var length = botChat[i].length - 1;
var index = Math.ceil( length * Math.random());
var reply = (botChat[i][index]);
send_message(reply);
}
}
}
}
and a typical line from my array is
new Array ("I need (.*)\." , "Why do you need $1?", "Would it really help you to get $1?" , "Are you sure you need $1?"),
i'm trying to demonstrate the ways of creating a chatbot. The first four responses work perfectly
it takes a name, comments on the weather and can search for cats. What it can't do is perform the loop. Has anyone any suggestions?

Cant get indexOf statement to work

Ultimately I am prompting the user for a guess, which is then ultimately changed so regardless of what the user inputs it will always Capitalize the first letter and make the rest lowercase. (Im doing this so if the user types in a guess the string will either match or not match the values in an array.) I tried doing a for statement to use a loops counter (3 total guesses is what im looking for). But when I try to use a indexOf to check the array, I keep getting an "unexpected token" error on that line that contains the indexOf statement. So the question would be (1) what am i doing wrong in this line of code?
//declare variables
var sportsArray = new Array("Football", "Basketball", "Rollerblading", "Hiking", "Biking", "Swimming");
var name = prompt("Enter your name");
var loops = 0;
var score = 0;
var sGuess = prompt("enter your sport guess");
// uses substrings to ultimately capitalize the 1st letter, and make everything after it lowerCase.
var sFirstPart = sGuess.substr(0, 1);
var sFirstCap = sFirstPart.toUpperCase();
var sSecondPart = sGuess.substring(1, sGuess.length);
var sSecondLow = sSecondPart.toLowerCase();
var usableGuess = sFirstCap + sSecondLow;
while(loops < 4){
if(sportsArray.indexOf(usableGuess) = 0 {
document.write("nice guess");
loops++;
}else {
document.write("loser");
loops++;
}
}

This works for checking the whole array:
var sportsArray = new Array("Football", "Basketball", "Rollerblading", "Hiking", "Biking", "Swimming");
var name = prompt("Enter your name");
var loops = 0;
var score = 0;
var sGuess = prompt("enter your sport guess");
// uses substrings to ultimately capitalize the 1st letter, and make everything after it lowerCase.
var sFirstPart = sGuess.substr(0, 1);
var sFirstCap = sFirstPart.toUpperCase();
var sSecondPart = sGuess.substring(1, sGuess.length);
var sSecondLow = sSecondPart.toLowerCase();
var usableGuess = sFirstCap + sSecondLow;
while(loops < 4){
if(sportsArray.indexOf(usableGuess) > -1) {
document.write("nice guess");
loops++;
}else {
document.write("loser");
loops++;
}
}
You'd want to use indexOf(guess) > -1 to check if the guess is present at any index of the array. For checking just one index position it would be indexOf(guess) == 0.

sportsArray.indexOf(usableGuess) === 0) instead of sportsArray.indexOf(usableGuess) = 0
It's a good practice to check for equality with constant on the left side. It will throw an exception in most browsers:
var a = 3;
if (12 = a) { // throws ReferenceError: invalid assignment left-hand side in Firefox
//do something
}
Also: use tools that provide static code analysis. A jslint.com or jshint.com for js is a good choice. There are also IDE plugins explicitely for that (using either of those two and more), see Is there a working JSLint Eclipse plug-in?.

Javascript array length through user input

I have a problem in Javascript I want to make a form which have one input text field and one button when I click on the button window.prompt is called.
It will prompt depend upon my array length but I want array length get through input text field when I write 10 it will prompt 10 times when I write 2 it will prompt 2 times.
How can i write this type of query?
I tried this code but its not working.
words = new Array (4);
function a() {
for ( k = 0 ; k < words.length ; k = k + 1 ) {
words[ k ] = window.prompt( "Enter word # " + k, "" ) ;
}
}

Maybe you forgot to call your function a().
Some remarks about your code:
You don't have to specify an initial array size, e.g. words = [] or words = new Array() is enough.
Also k=k+1 is usually written as k++.
A remark about asking questions:
Use punctuation to make sentences! Your whole question is one sentence.

Hopefully it's just the snippet of code but I hope you are using var somewhere to declare all those variables.
Otherwise this should do the trick, however not sure what you are trying to achieve but this sounds like a bad user experience.
Here is the jsffidle http://jsfiddle.net/R2bCz/1/
function Handler(event) {
var count = event.target.value;
var i = 0;
var words = [];
var word;
for (; i < count; i++) {
word = window.prompt("Enter word # " + i, "");
words.push(word);
}
}
$("#multi").on("change", Handler);

Javascript for Variations with Repetition (combinatorics) of missing string characters

My question is similar to THIS question that hasn't been answered yet.
How can I make my code (or any javascript code that might be suggested?) find all possible solutions of a known string length with multiple missing characters in variation with repetition?
I'm trying to take a string of known character lengths and find missing characters from that string. For example:
var missing_string = "ov!rf!ow"; //where "!" are the missing characters
I'm hoping to run a script with a specific array such as:
var r = new Array("A","B","C","D","E","F","G","H","I","J","K",
"L","M","N","O","P","Q","R","S","T","U","V",
"W","X","Y","Z",0,1,2,3,4,5,6,7,8,9);
To find all the possible variations with repetition of those missing characters to get a result of:
ovArfAow
ovBrfAow
ovCrfAow
...
ovBrfBow
ovBrfCow
...
etc //ignore the case insensitive, just to emphasize the example
and of course, eventually find ovErfLow within all the variations with repetition.
I've been able to make it work with 1 (single) missing character. However, when I put 2 missing characters with my code it obviously repeats the same array character for both missing characters which is GREAT for repition but I also need to find without repetition as well and might need to have 3-4 missing characters as well which may or may not be repeated. Here's what I have so far:
var r = new Array("A","B","C","D","E","F","G","H","I","J","K",
"L","M","N","O","P","Q","R","S","T","U","V",
"W","X","Y","Z",0,1,2,3,4,5,6,7,8,9);
var missing_string = "he!!ow!r!d";
var bt_lng = missing_string.length;
var bruted="";
for (z=0; z<r.length; z++) {
for(var x=0;x<bt_lng;x++){
for(var y=0;y<r.length;y++){
if(missing_string.charAt(x) == "!"){
bruted += r[z];
break;
}
else if(missing_string.charAt(x) == r[y]){
bruted += r[y];
}
}
}
console.log("br: " + bruted);
bruted="";
}
This works GREAT with just ONE "!":
helloworAd
helloworBd
helloworCd
...
helloworLd
However with 2 or more "!", I get:
heAAowArAd
heBBowBrBd
heCCowCrCd
...
heLLowLrLd
which is good for the repetition part but I also need to test all possible array M characters in each missing character spot.

Maybe the following function in pure javascript is a possible solution for you. It uses Array.prototype.reduce to create the cartesian product c of the given alphabet x, whereby its power n depends on the count of the exclamation marks in your word w.
function combinations(w) {
var x = new Array(
"A","B","C","D","E","F","G","H","I","J","K",
"L","M","N","O","P","Q","R","S","T","U","V",
"W","X","Y","Z",0,1,2,3,4,5,6,7,8,9
),
n = w.match(/\!/g).length,
x_n = new Array(),
r = new Array(),
c = null;
for (var i = n; i > 0; i--) {
x_n.push(x);
}
c = x_n.reduce(function(a, b) {
var c = [];
a.forEach(function(a) {
b.forEach(function(b) {
c.push(a.concat([b]));
});
});
return c;
}, [[]]);
for (var i = 0, j = 0; i < c.length; i++, j = 0) {
r.push(w.replace(/\!/g, function(s, k) {
return c[i][j++];
}));
}
return r;
}
Call it like this console.log(combinations("ov!rf!ow")) in your browser console.

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