Develop Reference

Get Parameter from URL and use it in dictionary

i have basically 0 programming experience. So here is my question. I am Using a JS to get some Parameters from URL and use it with the HTML, and it works.
This is the code:
function qs(search_for) {
var query = window.location.search.substring(1);
var parms = query.split('&');
for (var i=0; i<parms.length; i++) {
var pos = parms[i].indexOf('=');
if (pos > 0 && search_for == parms[i].substring(0,pos)) {
return parms[i].substring(pos+1);;
}
}
return "";
}
and in HTML
<script type="text/javascript">document.write(qs("name"));</script>
Now, let's say I want to use the Value of the Parameters to generate a specific Text on the page. But I do not want to use the Parameter itself, but rather use a kind of Dictionary, to match a Parameter to a String.
for Example
a1 : "Good morning"
b2 : "Good evening"
I have tried something linke this, with no success, can someone help?:
function qs(search_for) {
var dict = {}
dict[a1] = "Good morning";
dict[b2] = "Good evening";
var query = window.location.search.substring(1);
var parms = query.split('&');
for (var i=0; i<parms.length; i++) {
var pos = parms[i].indexOf('=');
if (pos > 0 && search_for == parms[i].substring(0,pos)) {
if parms[i].substring(pos+1) in dict {
return dict[parms[i].substring(pos+1)];;
}
}
}
return "";
}
Thanks in advance!
L
EDIT: Just to be clear, I do not want to read Parameters "a1" and "b2". I rather want that when a certain Parameter equals "a1" the function returns "Good morning" and when a certain parameter equals "b2" the function returns "Good evening"

You do this:
function getParam(param){
var both = location.search.replace('?', '').split('&');
for(var i=0,a,l=both.length; i<l; i++){
a = both[i].split('=');
if(a[0] === encodeURIComponent(param)){
return decodeURIComponent(a[1]);
}
}
return undefined;
}
var useInDict = getParam('a1');
Assumes raw url encode.

function parseGETfromUrl ( query = location.search.substring( 1 ) ) {
let parameters = {};
for ( const [ name, value ] of new URLSearchParams( query ) ) parameters[name] = value;
return parameters;
}
//Test code
let paramsString = "q=URLUtils.searchParams&topic=api";
parseGETfromUrl( paramsString ); // { q: "URLUtils.searchParams", topic: "api" }
parseGETfromUrl(); //Same result as above, when url ends with "?q=URLUtils.searchParams&topic=api"
Heading function parseGETfromUrl returns an object which contains information of url query string.

Javascript Function to split and return a value from a string

I am trying to grab a certain value. I am new to javascript and I can't figure out why this is not working.
If I parse "kid_2" I should get "kostas". Instead of "Kostas" I always get "02-23-2000". So I must have a logic problem in the loop but I am really stuck.
function getold_val(fieldname,str){
var chunks=str.split("||");
var allchunks = chunks.length-1;
for(k=0;k<allchunks;k++){
var n=str.indexOf(fieldname);
alert(chunks[k]);
if(n>0){
var chunkd=chunks[k].split("::");
alert(chunkd);
return chunkd[1];
}
}
}
var test = getold_val('kid_2','date_1::02-23-2000||date_2::06-06-1990||kid_1::George||kid_2::Kostas||');
alert(test);

A regex may be a little more appealing. Here's a fiddle:
function getValue(source, key){
return (new RegExp("(^|\\|)" + key + "::([^$\\|]+)", "i").exec(source) || {})[2];
}
getValue("date_1::02-23-2000||date_2::06-06-1990||kid_1::George||kid_2::Kostas||","kid_2");
But if you want something a little more involved, you can parse that string into a dictionary like so (fiddle):
function splitToDictionary(val, fieldDelimiter, valueDelimiter){
var dict = {},
fields = val.split(fieldDelimiter),
kvp;
for (var i = 0; i < fields.length; i++) {
if (fields[i] !== "") {
kvp = fields[i].split(valueDelimiter);
dict[kvp[0]] = kvp[1];
}
}
return dict;
}
var dict = splitToDictionary("date_1::02-23-2000||date_2::06-06-1990||kid_1::George||kid_2::Kostas||","||","::");
console.log(dict["date_1"]);
console.log(dict["date_2"]);
console.log(dict["kid_1"]);
console.log(dict["kid_2"]);​

This works, here's my fiddle.
function getold_val(fieldname,str) {
var chunks = str.split('||');
for(var i = 0; i < chunks.length-1; i++) {
if(chunks[i].indexOf(fieldname) >= 0) {
return(chunks[i].substring(fieldname.length+2));
}
}
}
alert(getold_val('kid_2', 'date_1::02-23-2000||date_2::06-06-1990||kid_1::George||kid_2::Kostas||'));
The issue with your code was (as #slebetman noticed as well) the fact that a string index can be 0 because it starts exactly in the first letter.
The code is almost the same as yours, I just didn't use the second .split('::') because I felt a .substring(...) would be easier.

There are two bugs. The first error is in the indexOf call:
var n = str.indexOf(fieldname);
This will always return a value greater than or equal to 0 since the field exists in the string. What you should be doing is:
var n = chunks[k].indexOf(fieldname);
The second error is in your if statement. It should be:
if(n >= 0) {
...
}
or
if(n > -1) {
...
}
The substring you are looking for could very well be the at the beginning of the string, in which case its index is 0. indexOf returns -1 if it cannot find what you're looking for.
That being said, here's a better way to do what you're trying to do:
function getold_val(fieldName, str) {
var keyValuePairs = str.split("||");
var returnValue = null;
if(/||$/.match(str)) {
keyValuePairs = keyValuePairs.slice(0, keyValuePairs.length - 1);
}
var found = false;
var i = 0;
while(i < keyValuePairs.length && !found) {
var keyValuePair = keyValuePairs[i].split("::");
var key = keyValuePair[0];
var value = keyValuePair[1];
if(fieldName === key) {
returnValue = value;
found = true;
}
i++;
}
return returnValue;
}

Append number to a comma separated list

the list looks like:
3434,346,1,6,46
How can I append a number to it with javascript, but only if it doesn't already exist in it?

Assuming your initial value is a string (you didn't say).
var listOfNumbers = '3434,346,1,6,46', add = 34332;
var numbers = listOfNumbers.split(',');
if(numbers.indexOf(add)!=-1) {
numbers.push(add);
}
listOfNumbers = numbers.join(',');
Basically i convert the string into an array, check the existence of the value using indexOf(), adding only if it doesn't exist.
I then convert the value back to a string using join.

If that is a string, you can use the .split() and .join() functions, as well as .push():
var data = '3434,346,1,6,46';
var arr = data.split(',');
var add = newInt;
arr.push(newInt);
data = arr.join(',');
If that is already an array, you can just use .push():
var data = [3434,346,1,6,46];
var add = newInt;
data.push(add);
UPDATE: Didn't read the last line to check for duplicates, the best approach I can think of is a loop:
var data = [3434,346,1,6,46];
var add = newInt;
var exists = false;
for (var i = 0; i < input.length; i++) {
if (data[i] == add) {
exists = true;
break;
}
}
if (!exists) {
data.push(add);
// then you would join if you wanted a string
}

You can also use a regular expression:
function appendConditional(s, n) {
var re = new RegExp('(^|\\b)' + n + '(\\b|$)');
if (!re.test(s)) {
return s + (s.length? ',' : '') + n;
}
return s;
}
var nums = '3434,346,1,6,46'
alert( appendConditional(nums, '12') ); // '3434,346,1,6,46,12'
alert( appendConditional(nums, '6') ); // '3434,346,1,6,46'
Oh, since some really like ternary operators and obfustically short code:
function appendConditional(s, n) {
var re = new RegExp('(^|\\b)' + n + '(\\b|$)');
return s + (re.test(s)? '' : (''+s? ',':'') + n );
}
No jQuery, "shims" or cross-browser issues. :-)

jQuery removing values from a comma separate list

Given an input like:
<input type="test" value="3,4,9" />
What's the best way to remove a value like 9, 4 or 3, without having issues with the commas, I don't want this ending up:
value="3,4,"
value="3,,9"
value=",4,9"
Is there a clean way to get this done in JavaScript/jQuery?

You could split your value into an array, then filter out values you do not want.
$("input[type='test']").val().split(",") // ["3","4","9"]
.filter(function(v){return !isNaN(parseInt(v))}) // filter out anything which is not 0 or more
Here is a less terse version which filters out anything which is not numeric
var array = $("input[type='test']").val().split(",");
// If you are dealing with numeric values then you will want
// to cast the string as a number
var numbers = array.map(function(v){ return parseInt(v)});
// Remove anything which is not a number
var filtered = numbers.filter(function(v){ return !isNaN(v)});
// If you want to rejoin your values
var joined = filtered.join(",");
Finally change the value on the input
$("input[type='test']").val(joined);

Similar to PHP implode/explode functions
Array.prototype.remove = function(from, to) {
var rest = this.slice((to || from) + 1 || this.length);
this.length = from < 0 ? this.length + from : from;
return this.push.apply(this, rest);
};
var explode = value.split(',');
explode.remove(1);
var implode = explode.join(',');
Documentation:
fce: Split
fce: Join
fce: Array.remove

No jQuery required :P
<script type="text/javascript">
//var subject = '3,4,9';
//var subject = '3,,9';
var subject = ',,4,9';
var clean = Array();
var i = 0;
subject = subject.split(',');
for (var a in subject)
{
if(subject[a].length)
{
clean[i] = subject[a];
i++;
}
}
document.write(clean.join(','));
</script>

You may also use pure javascript. Let say you want to take off only "4":
value = value.replace(/4,?/, '')
or "3" and "9":
value = value.replace(/([39],?)+/, '')

I think this function will work for what you are trying to do: http://www.w3schools.com/jsref/jsref_split.asp
string.split(separator, limit)

use
array = string.split(separator);
to break a string into an array. then use this to join after manipulations.
string = array.join(separator);

var ary = value.split(',');
ary.splice(indexOfItemToRemove,1)
var result = ary.join(',');

This is discussed in another post:
remove value from comma separated values string
var removeValue = function(list, value, separator) {
separator = separator || ",";
var values = list.split(",");
for(var i = 0 ; i < values.length ; i++) {
if(values[i] == value) {
values.splice(i, 1);
return values.join(",");
}
}
return list;
}

You can use this function:
function removeComma(x) {
var str = '';
var subs = '';
for(i=1; i<=x.length; i++) {
subs = x.substring(i-1, i).trim();
if(subs !== ',') {
str = str+subs;
}
}
return str;
}

Javascript onclick get url value

I will like to get a url value upon onclick.
like this:
www.google.com/myfile.php?id=123
I want to get id and its value.

window.location.search will get you the ?id=123 part.

After reading the comments, it looks like you want a way to get the query string off a url, but not the current url.
function getParameters(url){
var query = url.substr(url.lastIndexOf('?'));
// If there was no parameters return an empty object
if(query.length <= 1)
return {};
// Strip the ?
query = query.substr(1);
// Split into indivitual parameters
var parts = query.split('&');
var parameters = {};
for(var i = 0; i < parts.length; i++) {
// Split key and value
var keyValue = parts[i].split('=');
parameters[keyValue[0]] = keyValue[1] || '';
}
return parameters;
}
function alertId(a){
var parameters = getParameters(a.href);
alert(parameters.id);
}
//onclick="alertId(this); return false;"