newbie question:
i am using a simple for loop in my code. Let's say this returns 3 pozitive values of a, b and c. What i want is to have all 3 values described as different variables to use later outside the loop. Is it possible? Sample code:
var CampAdGR = ss.getRange("A9").getValue();
var data = ss.getRange("A23:A").getValues();
for (var i = 0; i < data.length; i++) {
if (data[i][0] == CampAdGR) {*continue code*}
Thanks!
If you have an array of values, you can either declare the variables seperately:
var data = [ 1, 2, 3 ];
var a = data[ 0 ];
var b = data[ 1 ];
var c = data[ 2 ];
console.log( a );
console.log( b );
console.log( c );
Or you could use destructuring to set them in one line:
const data = [ 1, 2, 3 ];
const [ a, b, c ] = data;
console.log( a );
console.log( b );
console.log( c );
If you don't know in advance how many values you'll have inside the data, it's better to just keep working with the entire data array, since transforming the data can be done with array.map(), array.forEach() etc.
You can declare a different variable, usually an array, and use it as a storage.
var CampAdGR = ss.getRange("A9").getValue();
var data = ss.getRange("A23:A").getValues();
var storage = [];
for (var i = 0; i < data.length; i++) {
if (data[i][0] == CampAdGR) {
storage.push(data[i]);
}
}
storage.map( storedValue => {
console.log(storedValue);
});
If you need 3 different storage, declare 3 variables or save them on a single object.
The loop will create new variable names at run time (varName1, varName2, varName3...).
I concatenate the index i with the varName for unique variable names (it seems logic to me because the index is the only value changing throughout the loop).
The output will give you n times new variables (depending on how big your data array is) with their corresponding values.
var CampAdGR = ss.getRange("A9").getValue();
var data = ss.getRange("A23:A").getValues();
for (var i = 0; i < data.length; i++) {
if (data[i][0] == CampAdGR) {
var varName = varName.concat('aName' + data[i]);
}
}
Related
I am facing an issue when populating an array of the object dynamically in javascript. I have this sample data as below:
I have to populate following arrays with the data from above:
c1_Arr = [];
c2_Arr = [];
var torontoObj = { arName: 'تورونتو', enName: 'Totonto', value: 0 };
var parisObj = { arName: 'باريس', enName: 'Paris', value: 0 };
var londonObj = { arName: 'لندن', enName: 'London', value: 0 };
Now I am looping through the data to set the values from data as:
var resultCount = results.features.length;
for (var i = 0; i < resultCount; i++) {
var data = results.features[i].attributes;
parisObj.value = data.Paris;
londonObj.value = data.London;
torontoObj.value = data.Toronto;
if (data.Ind_ID === 101) {
c1_Arr.push(parisObj);
c1_Arr.push(londonObj);
c1_Arr.push(torontoObj);
}
}
console.log(c1_Arr);
I am getting this data in console:
Here I am getting the values of the object i.e. Ind_ID = 102 instead of the object values of Ind_ID = 101 (first object).
How to get the values of the required object using the Ind_ID?
The problem is because even though you have the if condition there but you are updating the value of the objects in the loop and since you have already pushed them objects you still have the reference in the main objects. They get overwritten.
Create the 3 objects (torontoObj, etc.) inside the loop.
Reference is getting updated in the second iteration (where Ind_ID is 102)
You should rather do
var resultCount = results.features.length;
for (var i = 0; i < resultCount; i++) {
var data = results.features[i].attributes;
if (data.Ind_ID === 101) {
parisObj.value = data.Paris;
londonObj.value = data.London;
torontoObj.value = data.Toronto;
c1_Arr.push(parisObj);
c1_Arr.push(londonObj);
c1_Arr.push(torontoObj);
}
}
console.log(c1_Arr);
Your object values are getting updated even after being set inside the if loop, simply because, you're not limiting it from being updated.
You could probably do one of the following 2 things:
The simpler one:
Extract the values of Paris, London and Toronto fields of data only if the Ind
_ID is 101.
like this:
var resultCount = results.features.length;
for (var i = 0; i < resultCount; i++) {
var data = results.features[i].attributes;
if (data.Ind_ID === 101) {
parisObj.value = data.Paris;
londonObj.value = data.London;
torontoObj.value = data.Toronto;
c1_Arr.push(parisObj);
c1_Arr.push(londonObj);
c1_Arr.push(torontoObj);
}
}
console.log(c1_Arr);
The more elegant one:
Extract the array element which only matches your condition, in other words filter.
var resultCount = results.features.length;
var data = results.features.filter(feature => feature.attributes.Ind_ID === 101);
parisObj.value = data[0].Paris;
londonObj.value = data[0].London;
torontoObj.value = data[0].Toronto;
console.log(c1_Arr);
I realize this is a somewhat off manner of operations, but for the sake of possibility, I'm wondering if anyone can help?
Here array2 is holding the end state I would like array1 to hold (only I want to do it with the for loop. It's fine that each sub_array's have to be initialized as their own variables, I'm just trying to get the array1 to hold N number of sub_arrays via the loop.
Here is the example I've tried, but trying to "compile" it via a string doesn't allow the sub_arrays to be called in a useable manner.
var numberOfSubArrays = 3
var sub_array1 = []
var sub_array2 = []
var sub_array3 = []
var array1 = []
var array2 = [sub_array1,sub_array2,sub_array3]
for (var i = 0; i < numberOfSubArrays; i++) {
array1[i] = "sub_array" + i
}
Any thoughts would be much appreciated!
var numberOfSubArrays = 3
var sub_array1 = [1]
var sub_array2 = [2]
var sub_array3 = [3]
var array1 = []
// we don't need array2 at all
//var array2 = [sub_array1,sub_array2,sub_array3]
// you need to count from 1..n, as you named your sub_arrays like that
for (var i = 1; i <= numberOfSubArrays; i++) {
// you can use eval, but be careful, eval is evil!
array1[i-1] = eval("sub_array" + i)
}
console.log(array1);
Using eval is yucky. This will work in browsers:
var numberOfSubArrays = 3
var sub_array1 = []
var sub_array2 = []
var sub_array3 = []
var array1 = []
var array2 = [sub_array1,sub_array2,sub_array3]
for (var i = 0; i < numberOfSubArrays; i++) {
array1[i] = window["sub_array" + i + 1];
}
In browsers, "global" vars are really objects in "window".
Note: this will not work in tools like jsfiddle, because they put your code inside a function (that you don't see).
I find numerous guides on how to add variables to existing objects, but nowhere how to add an "existing" variable to an existing object.
I have a whole list with variables already defined in my script. e.g.: a, b, c, d.
and they all have their own values.
Now I want to call a function on all these variables and then show the variable-names and outcome in console.
Therefor I want to create an object out of them to loop through. How do I do this?
This is my workflow:
Values are created in various places in the script:
a = 1.333;
b = 1.64252345;
c = 2.980988;
I create the object and try to add the already existing variables (this is where I fail):
var abc = {};
abc.a;
abc.b;
abc.c;
I want to loop through the object, flooring all numbers, and printing the variable-name with the returned number:
var i;
for (i = 0; i < abc.length; ++i) {
var variablename = Object.keys(abc[i]);
var flooredvalue = floor(abc[i]);
var abc[i] = flooredvalue; // Save the floored value back to the variable.
console.log(variablename+": "+flooredvalue);
}
My desired output in console.log:
a = 1
b = 1
c = 2
Looping through the array of object keys will be a good idea.
a = 1.333;
b = 1.64252345;
c = 2.980988;
var abc = {};
abc.a = a;
abc.b = b;
abc.c = c;
var i;
var keys = Object.keys(abc);
console.log(abc['a'])
for (i = 0; i < keys.length; i++) {
var key = keys[i];
var flooredvalue = Math.floor( abc[key] );
abc[key] = flooredvalue;
window[key] = flooredvalue; //global variable change.
}
console.log(a);
console.log(b);
console.log(c);
I am trying to build an array that should look like this :
[
[{"name":"Mercury","index":0}],
[{"name":"Mercury","index":1},{"name":"Venus","index":1}],
[{"name":"Mercury","index":2},{"name":"Venus","index":2},{"name":"Earth","index":2}],
...
]
Each element is the concatenation of the previous and a new object, and all the indexes get updated to the latest value (e.g. Mercury's index is 0, then 1, etc.).
I have tried to build this array using the following code :
var b = [];
var buffer = [];
var names = ["Mercury","Venus","Earth"]
for (k=0;k<3;k++){
// This array is necessary because with real data there are multiple elements for each k
var a = [{"name":names[k],"index":0}];
buffer = buffer.concat(a);
// This is where the index of all the elements currently in the
// buffer (should) get(s) updated to the current k
for (n=0;n<buffer.length;n++){
buffer[n].index = k;
}
// Add the buffer to the final array
b.push(buffer);
}
console.log(b);
The final array (b) printed out to the console has the right number of objects in each element, but all the indexes everywhere are equal to the last value of k (2).
I don't understand why this is happening, and don't know how to fix it.
This is happening because every object in the inner array is actually the exact same object as the one stored in the previous outer array's entries - you're only storing references to the object, not copies. When you update the index in the object you're updating it everywhere.
To resolve this, you need to create new objects in each inner iteration, or use an object copying function such as ES6's Object.assign, jQuery's $.extend or Underscore's _.clone.
Here's a version that uses the first approach, and also uses two nested .map calls to produce both the inner (variable length) arrays and the outer array:
var names = ["Mercury","Venus","Earth"];
var b = names.map(function(_, index, a) {
return a.slice(0, index + 1).map(function(name) {
return {name: name, index: index};
});
});
or in ES6:
var names = ["Mercury","Venus","Earth"];
var b = names.map((_, index, a) => a.slice(0, index + 1).map(name => ({name, index})));
Try this:
var names = ["Mercury","Venus","Earth"];
var result = [];
for (var i=0; i<names.length; i++){
var _temp = [];
for(var j=0; j<=i; j++){
_temp.push({
name: names[j],
index:i
});
}
result.push(_temp);
}
console.log(result)
try this simple script:
var b = [];
var names = ["Mercury","Venus","Earth"];
for(var pos = 0; pos < names.length; pos++) {
var current = [];
for(var x = 0; x < pos+1; x++) {
current.push({"name": names[x], "index": pos});
}
b.push(current);
}
I have a js object which looks like this:
var detailsArray = [
{a0 :1,
b0 :'A'},
{a1 :2,
b1 :'B'},
{a2 :3,
b2 :'C'},
{a3 :4,
b3 :'D'}];
This is how the object is created from the server side. On the client side I want to retrieve the value of all 'a's and add them to an array. The problem is that the variable name is changing depending on the index number. I have tried using underscore.js to do something like this:
var variableA = new Array();
for(var i = 0;i<detailsArray.length;i++){
var temp = 'a' + i;
variableA[i] = _.pluck(detailsArray,temp);
}
But this does not work. Can anyone tell how to get the values??
There is two ways for accessing properties of object in javascript : using the dot like you just done, or using the array syntax style.
var obj = {'a':5};
obj.a
obj['a']
So with your code, this would give this :
var variableA = new Array();
for(var i = 0;i<detailsArray.length;i++){
variableA[i] = detailsArray[i]['a' + i];
}
With underscore, you could do:
_.reduce(_.map(detailsArray, function(o, i) {
return o['a' + i];
}), function(a, b) {
return a + b;
});
And with native JS in newer browsers:
detailsArray.map(function(o, i) {
return o['a' + i];
}).reduce(function(a, b) {
return a + b;
});
You can also do it like that:
for (var i = 0; i < detailsArray.length; i++)
alert(eval("detailsArray[" + i + "].a" + i));
The code I provide will alert all the values corresponding to as in the json array, but obviously you can do whatever you want with the values obtained.
Here I am counting that all the keys will be of the kind a smth, but I suppose this is a safe assumption.
here's one possible implementation
var tmp = [];
for (var i = 0; i < detailsArray.length; i++) {
var obj = detailsArray[i]; // current object at index
for (var props in obj) { // iterate properties in current object
if (props.charAt() == "a") { // if starts with a....
tmp.push(obj[props]); // add value to array
break; // stop the property iteration and move to next object
}
}
}
console.log(tmp); // [1,2,3,4]