Develop Reference

angularjs: check for an id exists in an array r not

var vm = this;
vm.usableDeposits = [];
for (var i = 0; i < billableChargeCodes.length; i++) {
var deposits = usableDeposits.filter(function(ud) {
return ud.billinggroupuid == billableChargeCodes[i].billinggroupuid ||
ud.billinggroupuid == billableChargeCodes[i].billingsubgroupuid ||
ud.departmentuid == billableChargeCodes[i].departmentuid ||
!ud.entypeuid ||
ud.entypeuid == entypeuid
})
for (var i = 0; i < deposits.length; i++) {
var depositid = deposits[i]._id;
first time, vm.usableDeposits[] is empty. I have to check deposits[i]._id exists in vm.usableDeposits[] or not. How to check vm.usableDeposits[] empty array _id with deposits[i]._id? if id not exists in vm.usableDeposits[], then i want to push the element into vm.usableDeposits[]

You can simply use the indexOf operator in JavaScript to check if a value exists in the array or not. It returns -1 if the value is not in the array, else, it returns the index of the element in the array.
The syntax goes like this -
if(myArray.indexOf(value) !== -1) {
// do this
} else {
// do that
}
Hope this helps.

You can use .some
deposits.some(o=> vm.usableDeposits.indexOf(o.id))
to check if the ID in deposits array is in vm.usableDeposits. .some will return true if condition is true and false otherwise

$scope.findIndexInData = function(data, property, value) {
var result = -1;
if((!!data) && (!!property) && (!!value)){
data.some(function (item, i) {
if (item[property] === value) {
result = i;
return true;
}
});
}
return result;
}
Pass on the array as the First Element. Property as second element and value you are looking in that array.
Example:
array = [{id:"1234",name:"abc"}, {id:"4567",name"xyz"}]
So you need to call:
index = $scope.findIndexInData(array , 'id' , 4567)

Find the index of a sub array that contains a number

var array = [[2,3,4],[4,5,6],[2,3,9]];
var number = 9;
If I have this nested array and this variable how do I return the index
where the sub-array with the number is. So the final result should be 2 or.
So far I have:
var indexOfRemainingArray = array.filter(function(item,i) {
if(item != number) {
return i;
}
});
I would like to know how to use map or filter functions for this.

Use Array#findIndex to find the index, and use Array#indexOf in the callback to check if the sub array contains the number at least once.
var array = [[2,3,4],[4,5,6],[2,3,9]];
var number = 9;
var indexOfRemainingArray = array.findIndex(function(sub) {
return sub.indexOf(number) !== -1;
});
console.log(indexOfRemainingArray);
And if you need both indexes, you can assign the result of the inner indexOf to a variable:
var array = [[2,3,4],[4,5,9],[2,3,1]];
var number = 9;
var innerIndex;
var indexOfRemainingArray = array.findIndex(function(sub) {
innerIndex = sub.indexOf(number);
return innerIndex !== -1;
});
console.log(indexOfRemainingArray, innerIndex);

How to count same items with specail form in a array (javascript)

For example:
input: var arr = ['a','b','c','a-5','c-2'];
output: var result = {'a':6,'b':1,'c':'3'} ;
My solution is:
function countSameItem(arr) {
var counter = {};
for (var i = 0; i < arr.length; i++) {
var item = arr[i].split('-');
if (item.length === 1) {
counter[item] = (counter[item] + 1) || 1;
} else {
counter[item[0]] = (counter[item[0]] + parseInt(item[1]) || parseInt(item[1]));
}
}
return counter;
}
But I want to thought a more consise solution using the lodash

You can do it concisely without lodash:
var result = ['a','b','c','a-5','c-2'].reduce(function(o, s) {
var a = s.split('-').concat(1);
return o[a[0]] = (o[a[0]] || 0) + +a[1], o;
}, Object.create(null));

with lodash you would use the _.reduce function in a similar manner to the way Oriol uses the native reduce function
function countSameItem(arr) {
return _.reduce( arr, function(counter, n, i) {
var narr=n.split('-');
counter[narr[0]] = (counter[narr[0]] || 0) + (1*narr[1] || 1);
return counter;
}, {});
}
counter is the accumulator and what is eventually returned from the function.
n is each element
i is the index of each element.
for each element in the input array counter gets the value returned by the last element that was ran. The third argument in _.reduce gives the initial value of counter.
Using the native implementation is probably better unless you are using lodash for other features and want consistency in the code.
The lodash version of reduce does have the benefit of working on objects as well as arrays but this can be done natively as well by using Object.keys(arr).reduce

Get full value from array using partial value

I have an array like this:
var array = ["xs-1", "sm-10", "md-4"];
Now I want to get the number at the end of a particular value. For example I want to search the array for "md-" and see what number is at the end of that string (should return 4).
I can't do array.indexOf("xs-") because that isn't the whole value. Is there a way to do this?

Using a for loop:
var array = ["xs-1", "sm-10", "md-4"];
var search = "md-";
var found = null;
for (var i = 0; i < array.length; i++) {
if (array[i].indexOf(search) === 0) {
found = array[i];
break; // Note: this is assuming only one match exists - or at least you are
// only interested in the first match
}
}
if (found) {
alert(found);
} else {
alert("Not found");
}
Using .filter:
var array = ["xs-1", "sm-10", "md-4"];
var search = "md-";
var filtered = array.filter(function(item) {
return item.indexOf(search) === 0;
});
// note that here filtered will contain all matched elements, so it might be more than
// one match.
alert(filtered);
Building from #János Weisz's suggestion, you can easily transform your array into an object using .reduce:
var array = ["xs-1", "sm-10", "md-4"];
var search = "md";
var obj = array.reduce(function(prev, item) {
var cells = item.split("-");
prev[cells[0]] = cells[1];
return prev;
}, {});
// note: at this point we have an object that looks like this:
// { xs:1, sm:10, md: 4 }
// if we save this object, we can do lookups much faster than looping
// through an array
// now to find "md", we simply do:
alert(obj[search]);
If you need to do multiple look ups from the same source array, then transforming it into an object may be the most efficient approach overall. You pay the initial price of the transformation, but after than lookups are O(1) versus O(n) for each time you have to search your array. Of course, if you only ever need one item, then probably don't bother.

I recommend using objects for this:
var array = [{'type': 'xs', 'value': 1}, {'type' : 'sm', 'value': '10'}, {'type' : 'md', 'value': '4'}];
This way you can search the array as:
function searchMyArrayByType(array, type) {
var items[];
for (var i = 0; i < array.length; i++)
{
if (array[i].type == type) items.push(array[i].value);
}
return items;
}
var valuesWithMd = searchMyArrayByType(array, 'md');
For more information regarding the structure and use of objects, please refer to https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_Objects

You can create a method that takes the prefix you're looking for, the array, and the split character and returns all the numbers in an array:
function findNumberFromPrefix(prefix, arr, splitChar) {
var values = [];
for (var i = 0; i < arr.length; i++) {
if (arr[i].indexOf(prefix) === 0) {
values.push(arr[i].split(splitChar)[1]);
}
}
return values;
}
And call it:
var array = ["xs-1", "sm-10", "md-4"];
var values = findNumberFromPrefix("md-", array, "-");
console.log(values); //["4"]
Demo: http://jsfiddle.net/rn4h9msh/

A more functional approach and assuming you can have have more than one element with the same prefix:
function findPrefix(array, prefix) {
return array.filter(function (a) { return a.indexOf(prefix) === 0; })
.map(function (e) { return e.slice(prefix.length); })
}

If you have only one matching element, do a loop like this:
var array = ["xs-1", "sm-10", "md-4"];
var needle = "md-";
for(i=0;i<array.length;i++) {
if(array[i].indexOf(needle) == 0)
alert(array[i].substr(needle.length, array[i].length));
}
Demo: http://jsfiddle.net/kg0c43ov/

You can do it like this...
var array = ["xs-1", "sm-10", "md-4"];
getValue("md-");
function getValue(search) {
for(var key in array) {
if(array[key].indexOf(search) > -1) {
alert("Array key is: " + key);
alert("Array value is: " + array[key].replace(search, ""));
}
}
}
JSFiddle here.

Check for a value in Array

I'm trying to check for match in an array with PURE JAVASCRIPT. I don't know how to do this, I would appreciate your help.
var sites = new Array ("site1.com", "site2.com", "site3.com" ...);
// Sites array contains 100 values
var imgs = document.getElementsByTagName("img");
for (var i = 0; i < imgs.length; i++) {
img = imgs[i].src;
// I'm trying to check if is in array,
// and don't waste a lot of size in code
if(img.match(sites)){
notHere(imgs[i]);
}
// This is the working way.
// Even if location is a.site1.com/b/, it will match
if (img.match("site1.com")) {
heReload(imgs[i]);
}
// Repeat this piece of code 100 times
}
}
NOTE: I don't want to check for an exact value. I want to simulate the match() function so if img = "http://a.b.c/d/" and in array is "b.c/", it executes function().

Your "sites" variable should be a regular expression rather than an array:
var sites = /\b(site1\.com|site2\.com|etc|etc)\b/
later:
if (img.match(sites))
......
If for some reason you prefer to keep "sites" in an array, you also can create a regular expression "on the fly":
var sites = ["site1.com", "site2.com", "site3.com"]
var sitesRegexp = new RegExp("\\b(" + sites.join("|").replace(".", "\\.") + ")\\b")
....
if (img.match(sitesRegexp)
......

Good use case for filter.
If you want to have it working on "old" browser :
var nativeFilter = Array.prototype.filter;
_.filter = _.select = function(obj, iterator, context) {
var results = [];
if (obj == null) return results;
if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context);
each(obj, function(value, index, list) {
if (iterator.call(context, value, index, list)) results[results.length] = value;
});
return results;
};
It will return an empty array if nothing is found, otherwise, return an array containing the result(s)
> [1,2,3,4].filter(function(item) { return item == 4 } );
[ 4 ]
Source : Underscore.js
So now your code will look like this :
var sites = new Array ("site1.com", "site2.com", "site3.com" ...);
// Sites array contains 100 values
var imgs = document.getElementsByTagName( "img" );
for ( var i = 0; i < imgs.length; i++ ) {
var img = imgs[ i ].src;
var result = sites._filter( function( site ) {
return img.match( site )
});
// result is an array of matching sites
}

you can extend the Array prototype , so it supports all browsers ...
try this :
Array.prototype.myContains = function(obj) {
var i = this.length;
while (i--) {if (this[i] .indexOf(obj)>-1) return true; }
return false;
}
usage : var t=myArr.myContains(3);