i could not make it as function.Please help.When i modified as function and add button,it not work.
i'm newbie in javascript.i would like study by the simple script.But for the below script when i try to add "function xxx()" it not working with input button.
I try to solve by my own with google...failed.
<script>
var myStr = "xxx yyy zzz";
var strArray = myStr.split(" ");
// Display array values on page
for(var i = 0; i < strArray.length; i++){
document.write("<p>" + strArray[i] + "</p>");
}
</script>
Break your code into blocks if you ever are stuck on something. So first you are trying to break a string into an array so that's your first block. Then your second block would be to write it to the page. So we have our code basically written out in our heads.
---Break string
---Display broken string
So to make a function we need to write a function first
myFunction = function(){
};
But to get the function to be modular we need to be able to pass in variables
So we'll add two variables one being the string to pass through and one being the location to inject the looped broken text.
myFunction = function(str, location){
};
Now we have to do something with these variables.
myFunction = function(str, location){
///test if str is a string
if(typeof(str) == "string")
{
var l = str.split(" "); /// here we're spliting the string into an array by every space
if(l.length >= 1) ///test if there's atleast one item
for(i=0;i<l.length;i++) ///simple for loop
location.innerHTML += "This is a part of str " + l[i] + "<br>" ///you can do anything here you want to do.
}
};
Now as you can see it's modular at it's lowest point, this can be as complex as you want it. here is a test you can try out and mess around with. https://jsfiddle.net/s8pytzm3/1/
Related
I am working on a PDF with some scripting, and I am applying code to fields using the console and some simple loops to save on repeated efforts. In some cases, I am applying a custom calculation script to a field where one integer needs to change from one field to the next. If all the scripts were the same, I would run this in the debugger console:
var s = "if(this.getField(\"Span A\").value >= 60){\n\
event.value = Math.round(((this.getField(\"Span A\").value*41500 - 1674500)/233));\n\
}else{\n\
event.value = Math.round((this.getField(\"Span A\").value*3500/60));\n\
}";
for (var i = 0; i < this.numFields; i++){
var f = this.getField(getNthFieldName(i));
if(f.name.match(/quant a/i) != null){
var n = f.name.match(/\d/g);
f.setAction("Calculate", s);
}
}
I have many 'Quant' fields, and each group (A, B, etc) will have a similar calculation. The fields are name "Quant A1", "Quant A2" etc. Quant A1 needs to calculate with the input from Span A1.
In the above script, it would be really cool if I could have a variable within the script string that I can pass a value (n) to be plugged in to the string, essentially the same way a function call works.
Is this possible?
Here is my fantasy version of what I imagine it could look like (this is just to further explain my intent; I don't think this would actually work this way):
var s(x) = "if(this.getField(\"Span A\""x").value >= 60){\n\
event.value = Math.round(((this.getField(\"Span A\""x").value*41500 - 1674500)/233));\n\
}else{\n\
event.value = Math.round((this.getField(\"Span A\""x").value*3500/60));\n\
}";
for (var i = 0; i < this.numFields; i++){
var f = this.getField(getNthFieldName(i));
if(f.name.match(/quant a/i) != null){
var n = f.name.match(/\d/g);
f.setAction("Calculate", s(n));
}
}
You could use string litterals if you're useing ES6 and higher.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals?retiredLocale=nl
const greetings = "I'm a variable!";
let string = `Hi! this is a variable: ${greetings}`;
console.log(string);
Otherwise concatenate it with the + operator.
If I understand correctly your question. I think you want to use template literals.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals
Use backticks instead of " or ' to insert your variables inside a string.
const a ='Cheese'
const b= 'is Delicious'
${a} ${b} will output 'Cheese is Delicious'
I have a sentence stored in a variable.That sentence I need to extract into 4 parts depends on sentence which I have put into variables in my code,I can able to extract here and get into console but I am not getting the whole text of inside the bracket,only I am getting first words.Here is the code below.Can anyone please help me.
HTML
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<ul class="messages">
SCRIPT
$(document).ready(function() {
regex = /.+\(|\d. \w+/g;
maintext = "Welcome to project, are you a here(1. new user , 2. test user , 3. minor Accident or 4. Major Accident)";
matches = maintext.match(regex);
text_split0 = matches[0].slice(0, -1);
text_split1 = matches[1];
text_split2 = matches[2];
text_split3 = matches[3];
text_split4 = matches[4];
console.log(text_split0);
console.log(text_split1);
console.log(text_split2);
console.log(text_split3);
console.log(text_split4);
$(".messages").append('<li>'+text_split0+'</li><li>'+text_split1+'</li><li>'+text_split2+'</li><li>'+text_split3+'</li><li>'+text_split4+'</li>');
// $("li:contains('undefined')").remove()
});
function buildMessages(text) {
let messages = text.split(/\d\.\s/);
messages.shift();
messages.forEach((v)=>{
let msg = v.replace(/\,/,'').replace(/\sor\s/,'').trim();
$('.messages').append(`<li>${msg}</li>`);
// console.log(`<li>${msg}</li>`);
});
}
let sentenceToParse = "Welcome to project, are you a here(1. new user , 2. test user , 3. minor Accident or 4. Major Accident)";
buildMessages(sentenceToParse);
Use the split function on the String, keying on the digits (e.g. 1.), you will get the preface and each of the steps into an array.
Use the shift function on the Array removes the unneeded preface.
Use forEach to iterate over the values in the array, clean up the text.
Using replace to first remove commas, then remove or with spaces on either side.
Use trim to remove leading and training whitespace.
At this point, your array will have sanitized copy for use in your <li> elements.
If you're only concerned with working through a regex and not re-factoring, the easiest way may be to use an online regex tool where you provide a few different string samples. Look at https://www.regextester.com/
Ok, Try another approach, cause regex for this isn't the best way. Try this:
$(document).ready(function() {
// First part of sentence.
var mainText = "Welcome to project, are you a here(";
// Users array.
var USERS = ['new user', 'test user', 'minor Accident', 'Major Accident'];
var uSize = USERS.length;
// Construct string & user list dynamically.
for(var i = 0; i < uSize; i++) {
var li = $('<li/>').text(USERS[i]);
if(i === uSize - 1)
mainText += (i+1) + ". " + USERS[i] + ")";
else if(i === uSize - 2)
mainText += (i+1) + ". " + USERS[i] + " or ";
else
mainText += (i+1) + ". " + USERS[i] + " , ";
$(".messages").append(li);
}
console.log(mainText); // You will have you complete sentence.
}
Why that way is better? Simple, you can add or remove users inside the user array. String together with your user list will be updated automatically. I hope that help you.
World!
I'm trying to create a program in Javascript that takes the log of a number typed into an HTML input. Unfortunately i've encountered a problem where it wont accept the string with the .replace().
Its Function:
I.E: When log(10) is calculated, the function should first remove the first 4 char's "log(" next remove the last parenthesis ")" and then take the log of the no. between.
HTML includes style elements, button and input form and an output < DIV >.
//Function
function calculate()
{
var inputString = document.getElementById("inpstr");
var output = document.getElementById("output");
//TESTING CODE
/*
if (inputString.value.startsWith("log(").endsWith(")"))
{
console.log(output.innerHTML = inputString.value.substring(4, 20).replace(")", ""));
}
else
{
output.innerHTML = "false";
}
*/
//Math.log() calc *****DOESNT WORK*****
if (inputString.value.startsWith("log(").endsWith(")"))
{
output.innerHTML = Math.log(inputString.value.replace(")", "").substring(4, 20));
}
else
{
output.innerHTML = inputString.value;
}
event.preventDefault();
}
If someone can give me an effective solution that would be much appreciated.
Thanks,
Syntax
Since Math.log() accepts only number values and you're trying to pass a string to it, you should first parse this value into a float number and then pass it to the log function:
let val = parseFloat(inputString.value.replace(")", "").substring(4, 20));
output.innerHTML = Math.log(val);
I'm guessing I got downvoted for being lazy, so here is the quick info. Gonras got it right relating to what you want to extract, but he forgot to check that what's being input is actually a log.
That's where the regex below comes in handy! I'm matching the field to:
^ start of word, since we want to match the entire field.
log(
([-.\d])) any consecutive sequence () of numbers (\d), -, and '.', represented by the []. The \(...\) makes sure to save this inner part for later.
$ is end of word, see 1.
res will be null if there is no match. Otherwise, res[0] is the entire match (so the entire input field) and res[1] is the first 'capture group', at point 3 - which is presumably the number.
This of course fails for multiple "-" inside, or "." etc... so think it over.
//Function
function calculate()
{
var inputString = document.getElementById("inpstr");
var output = document.getElementById("output");
var res = /^log\(([-.\d]*)\)$/.exec(inputString.value);
if (res)
output.innerHTML = Math.log(res[1]);
else
output.innerHTML = res;
}
document.getElementById("output").innerHTML='start';
calculate()
<div id='output'></div>
<input id='inpstr' value='log(2.71828)'></input>
If I wanted to fix your if to supplement Gonras's solution:
if (inputString.value.startsWith("log(") && inputString.value.endsWith(")"))
Yours fails since startsWith() returns a boolean, which obviously doesn't have a endsWith function.
I'm working on my final project of the Winter 2017 quarter to demonstrate how to use Regular Expressions in both C# and JavaScript code behind pages. I've got the C# version of my demonstration program done, but the JavaScript version is making me pull what little hair I have left on my head out (no small achievement since I got a fresh buzz cut this morning!). The problem involves not getting any output after applying a Regular Expression in a While loop to get each instance of the expression and printing it out.
On my HTML page I have an input textarea, seven radio buttons, an output textarea, and two buttons underneath (one button is to move the output text to the input area to perform multiple iterations of applying expressions, and the other button to clear all textareas for starting from scratch). Each radio button links to a function that applies a regular expression to the text in the input area. Five of my seven functions work; the sixth is the one I can't figure out, and the seventh is essentially the same but with a slightly different RegEx pattern, so if I fix the sixth function, the seventh function will be a snap.
(I tried to insert/upload a JPG of the front end, but the photo upload doesn't seem to be working. Hopefully you get the drift of what I've set up.)
Here are my problem children from my JS code behind:
// RegEx_Demo_JS.js - code behind for RegEx_Demo_JS
var inputString; // Global variable for the input from the input text box.
var pattern; // Global variable for the regular expression.
var result; // Global variable for the result of applying the regular expression to the user input.
// Initializes a new instance of the StringBuilder class
// and appends the given value if supplied
function StringBuilder()
{
var strings = [];
this.append = function (string)
{
string = verify(string);
if (string.length > 0) strings[strings.length] = string;
}
this.appendLine = function (string)
{
string = verify(string);
if (this.isEmpty())
{
if (string.length > 0) strings[strings.length] = string;
else return;
}
else strings[strings.length] = string.length > 0 ? "\r\n" + string : "\r\n";
}
this.clear = function () { strings = []; };
this.isEmpty = function () { return strings.length == 0; };
this.toString = function () { return strings.join(""); };
var verify = function (string)
{
if (!defined(string)) return "";
if (getType(string) != getType(new String())) return String(string);
return string;
}
var defined = function (el)
{
// Changed per Ryan O'Hara's comment:
return el != null && typeof(el) != "undefined";
}
var getType = function (instance)
{
if (!defined(instance.constructor)) throw Error("Unexpected object type");
var type = String(instance.constructor).match(/function\s+(\w+)/);
return defined(type) ? type[1] : "undefined";
}
}
Within the code of the second radio button (which will be the seventh and last function to complete), I tested the ScriptBuilder with data in a local variable, and it ran successfully and produced output into the output textarea. But I get no output from this next function that invokes a While loop:
function RegEx_Match_TheOnly_AllInstances()
{
inputString = document.getElementById("txtUserInput").value;
pattern = /(\s+the\s+)/ig; // Using an Flag (/i) to select either lowercase or uppercase version. Finds first occurrence either as a standalone word or inside a word.
//result = pattern.exec(inputString); // Finds the first index location
var arrResult; // Array for the results of the search.
var sb = getStringBuilder(); // Variable to hold iterations of the result and the text
while ((arrResult = pattern.exec(inputString)) !==null)
{
sb.appendLine = "Match: " + arrResult[0] ;
}
document.getElementById("txtRegExOutput").value = sb.toString();
/* Original code from C# version:
// string pattern = #"\s+(?i)the\s+"; // Same as above, but using Option construct for case insensitive search.
string pattern = #"(^|\s+)(?i)the(\W|\s+)";
MatchCollection matches = Regex.Matches(userTextInput, pattern);
StringBuilder outputString = new StringBuilder();
foreach (Match match in matches)
{
string outputRegExs = "Match: " + "\"" + match.Value + "\"" + " at index [" + match.Index + ","
+ (match.Index + match.Length) + "]" + "\n";
outputString.Append(outputRegExs);
}
txtRegExOutput.Text = outputString.ToString();
*/
} // End RegEx_Match_The_AllInstances
I left the commented code in to show what I had used in the C# code behind version to illustrate what I'm trying to accomplish.
The test input/string I used for this function is:
Don’t go there. If you want to be the Man, you have to beat The Man.
That should return two hits. Ideally, I want it to show the word that it found and the index where it found the word, but at this point I'd be happy to just get some output showing every instance it found, and then build on that with the index and possibly the lastIndex.
So, is my problem in my While loop, the way I'm applying the StringBuilder, or a combination of the two? I know the StringBuilder code works, at least when not being used in a loop and using some test data from the site I found that code. And the code for simply finding the first instance of "the" as a standalone or inside another word does work and returns output, but that doesn't use a loop.
I've looked through Stack Overflow and several other JavaScript websites for inspiration, but nothing I've tried so far has worked. I appreciate any help anyone can provide! (If you need me to post any other code, please advise and I'll be happy to oblige.)
I'm attempting to write some code that puts a single string of emails into an array of emails. Splitting the string wherever there's a comma(,). The initial problem i'm having is the string that is being passed as a variable is not being recognized. I'm getting the error message "Cannot read property 'length' of undefined" of the conditional part of the for loop. Odd, as I'm definitely passing a string or trying to ?
When I pass in a string directly to the function parameter(to avoid the above problem for testing the rest of the function) only the first 2 email addresses appear the final email address is lost ?
I'm learning programming and this is an exercise as such I'm trying to avoid using the split() method or regEx. Daft i know.
Any help in overcoming these 2 issues greatly appreciated.
function separateCommaValues(text)
{
var input = [];
var val = '';
for(var i = 0; i < text.length; i++) {
if(text[i] == ',') {
if(val.length == 0){
continue;
}
input.push(val);
val = '';
} else {
val += text[i];
}
}
document.write( input );
}
separateCommaValues(str);
var str = "john#google.com, jake#yahoo.com, andrew#hotmail.com";
var str = "john#google.com, jake#yahoo.com, andrew#hotmail.com";
separateCommaValues(str);
This is the correct order. Your variable can be declared before it is used via hoisting, but you can't define it before it is used (undefined error).
And the last email address isn't pushed into the array because it doesn't have a comma after it. So after the loop, before document.write( input );, add something like this:
if(val.length > 0){
input.push(val);
val = '';
}