This question already has answers here:
How to get value at a specific index of array In JavaScript?
(8 answers)
Closed 2 years ago.
so I am currently learning javascript on Codecademy. And a weird kind of thing got introduced that I don't quite get.
if you look at the code. you see at the end in console that after logging animals it is a [i] like why is that there? I get that is has something to do with the for loop. But I don't quite understand like why or what that it does. I don't know if question is clear enough but if you just try to explain why it is there and what it does there. that would be greatly appreciated:)
const animals = ['Grizzly Bear', 'Sloth', 'Sea Lion'];
for (let i = 0; i < animals.length; i++){
console.log(animals[i]);
}
the bracket notation is used to specify the index of the array you are looping through. You can always read more about javascript arrays on w3schools
Related
This question already has an answer here:
How to merge each object within arrays by index?
(1 answer)
Closed 4 months ago.
This is the data:
data=[{"id":1,"name":"vikash","roll":39},{"id":2,"name":"kumar","roll":3}]
data2=[{"hobby":"football","food":"any"},{"hobby":"basketball","food":"any"}]
list1=[]
expected Output:
list1:[{"name":"vikash","roll":39,"hobby":"football","food":"any"},{"name":"kumar","roll":3,"hobby":"basketball","food":"any"}]
Please help me!
Providing both lists are the same length, you're happy there are no key conflicts and you're using Python...
data=[{"id":1,"name":"vikash","roll":39},{"id":2,"name":"kumar","roll":3}]
data2=[{"hobby":"football","food":"any"},{"hobby":"basketball","food":"any"}]
list1 = []
for k, v in enumerate(data):
list1.append({**v, **data2[k]})
print(list1)
However in the future please be more concise when asking your questions.
Specify the language
Don't include redundant tags (eg - this question has nothing to do with Django)
Tell us what you've tried!
Also... the "please help me" line isn't required. The whole purpose of this community is to help each other so again this is redundant!
A simpler to understand solution
data=[{"id":1,"name":"vikash","roll":39},{"id":2,"name":"kumar","roll":3}]
data2=[{"hobby":"football","food":"any"},{"hobby":"basketball","food":"any"}]
list1=[]
for i in range(len(data)):
del data[i]['id']
d_main = {}
d_main.update(data[i])
d_main.update(data2[i])
list1.append(d_main)
print(list1)
This question already has answers here:
ES6 template literals vs. concatenated strings
(4 answers)
Closed 1 year ago.
I'm start coding.
While I was watching a lecture, I saw code like this.
var coworkers = ['go', 'hello', 'hi', 'doit'];
<script type="text/javascript">
var i = 0;
while(i < coworkers.length){
document.write('<li>'+coworkers[i]+'</li>');
i = i + 1;
}
But But when I searched, Said to use ${variable} in JavaScript. and It didn't work.
How are +variable+ and ${variable} different in javascript? Thanks :)
Those placeholders, like ${variable}, can only be used in template literals, which are always enclosed in backticks(the key right below you escape key).
If it still doesn’t work, maybe you’re using an older browser?
This question already has answers here:
Why does changing an Array in JavaScript affect copies of the array?
(12 answers)
Closed 5 years ago.
I am stuck with a part of my google script code where one of array elements changed unexpectedly. It looks like a bug to me, but I'd like to hear from here if it's really is or just my coding error that I overlooked. Of course, I'm hoping for a solution as well in any case.
Here is that part of the code.
if (chkIn) {arr[1] = importData[i][1]+'2';
} else {
Logger.log((i)+' '+importData[i][1]);
Logger.log((i+1)+' '+importData[i+1][1]);
Logger.log((i+2)+' '+importData[i+2][1]);
Logger.log(arr[1]);
arr[1] = importData[i][1]+'1';
Logger.log('---------------------------------------------------');
Logger.log((i)+' '+importData[i][1]);
Logger.log((i+1)+' '+importData[i+1][1]);
Logger.log((i+2)+' '+importData[i+2][1]);
Logger.log(arr[1]);
};
(The if statement doesn't seem relevant here, but I included it just in case.)
Here is the output.
2573 2017122103
2574 20171221041
2575 20171221042
20171221042
---------------------------------------------------
2573 2017122103
2574 20171221041
2575 20171221031
20171221031
I really have no idea how importData[i+2][1] changed its value to arr[1] (the number after 2575).
Thank you in advance.
Probably this is because in your case:
arr === importData[i+2]
So when you change arr[1] you also have changed importData[i+2][1].
This question already has answers here:
What is the result of this javascript?
(3 answers)
Closed 5 years ago.
can you tell me what this code does as I need to understand it for a coding assessment. I only just started learning JavaScript
function getAttackString() {
var foo = "d323b8b34";
var bar = "x334q3j98";
return "The code is: "+(foo.substr(3,foo.length-6))+(bar.substr(2));
}
Thanks for your help
Start by looking up what .length and .substr are.
For example, what will foo.length give you? A good way to find out would be:
var x = "abc123";
console.log(x.length);
console.log is a command to print information to your web browser console, very helpful when doing debugging work.
This question already has answers here:
Determine whether an array contains a value [duplicate]
(18 answers)
Closed 9 years ago.
Is there a built-in function in javascript to do this or this is only the option to go? Please look at the code below:
var arr=[1,3,4,'+','-', or whatever]
function value_check(user_click){
var operators=['+','-','/','*','.']
for (var i=0;i<operators.length;i++){
if (arr[arr.length-1]==operators[i]){var value1='operator found';}
if (user_click==operators[i]){
var value2= value1;alert("consecutive operators"); break;
}
}
}
I think this code achieves what I intend to do but is there a simple and shorter way of doing this. In words, I want to achieve something like this:
if (arr[arr.length-1] && user_click BOTH ARE IN operators array)
alert("consecutive operators)
Yes, there are some options:
JavaScript indexOf()
jQuery.inArray()
arrayName.indexOf() is what you are looking for.