In the next version of ECMAScript (ECMAScript6 aka Harmony) will be for-of construct:
for (let word of ["one", "two", "three"]) {
alert(word);
}
for-of could be used to iterate over various objects, Arrays, Maps, Sets and custom iterable objects. In that sense it's very close to Python's for-in.
Top answer 1 of 3
12
In the next version of ECMAScript (ECMAScript6 aka Harmony) will be for-of construct:
for (let word of ["one", "two", "three"]) {
alert(word);
}
for-of could be used to iterate over various objects, Arrays, Maps, Sets and custom iterable objects. In that sense it's very close to Python's for-in.
2 of 3
6
for an array the most similar is the forEach loop (of course index is optional)
[1,2,3,4,].forEach(function(value,index){
console.log(value);
console.log(index);
});
So you will get the following output:
1
0
2
1
3
2
4
3
W3Schools
w3schools.com › python › python_for_loops.asp
Python For Loops
for loops cannot be empty, but ... have a for loop with no content, put in the pass statement to avoid getting an error. ... If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: sales@w3schools.com · If you want to report an error, or if you want to make a suggestion, send us an e-mail: help@w3schools.com · HTML Tutorial CSS Tutorial JavaScript Tutorial How To Tutorial SQL Tutorial Python Tutorial W3.CSS ...
How to convert JavaScript `for` loop to Python? - Stack Overflow
I am new to Python and want convert this small JavaScript code to Python. How can I do that? for (var y = 0; y More on stackoverflow.com
for loop in Python and for loop in Java: differences
One of my friend that works with Java said that there are two kind of for loops: for each, to iterate the code for every element in a variabile, and… More on reddit.com
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1
December 21, 2022Can someone please help a beginner with a loop?
Hi everyone, I am a beginner with coding in general, and learning an online course. We have a task to use a “for” loop to count spaces (" ") in a given string. I wrote a code that returns the right answer for one space, but failed to detect two spaces or no spaces (in that case i get an ... More on discuss.python.org
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0
March 24, 2023Asynchronous python vs asynchronous javascript
If you write async-await code in either Javascript or Python, it will ultimately run it single threaded, with concurrency being handled by an event loop. At a high level, you can regard them as more-or-less the same thing, but there are some subtle differences. Javascript has a built-in event loop, whereas in Python, there isn't an event loop built-in to the language, so you need to use one of the event loop libraries available, such as asyncio, curio or trio, which if you're not using an existing framework may also need some code to set it up. Also, the communication with the event loop is subtly different. In Python, an asynchronous task returns control to the event loop by yielding an awaitable (much like a generator) which the event loop must understand how and when to respond to (typically the awaitable is an object returned by one of the event loop library's methods). Whereas in Javascript a task returns control by adding a callback to a promise (or more generally, a "then-able") and then just returning. So in Javascript, it's easier to create user-defined awaitables (you just need to create an object with a then method), but part of the reason it's easier is that there's only one choice of event loop library. Python also supports threaded concurrency, and even threaded parallelism (although this is limited somewhat by the global interpreter lock - you can have multiple threads, but only one of them can be executing Python code at once), which for the most part Javascript does not (although WebWorkers implement shared-nothing parallelism, which is a start). This is at least somewhat orthogonal to async-await, although I suppose it's conceivable that someone could come up with a multi-threaded event loop library (a bit like in C#). More on reddit.com
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5
December 3, 2021Videos
JavaScript #22 For Loops with Examples
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#23 JavaScript for..of and for..in Loop | JavaScript for Beginners ...
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#12 JavaScript For Loop | JavaScript for Beginners Course - YouTube
06:58
#18 While vs For Loop | Which to use and When? - YouTube
23:12
JavaScript Loops Explained | For Loop, While and Do-While Loop ...
06:49
JavaScript Loops - YouTube
Medium
medium.com › @tbgarza2 › comparing-javascript-and-python-loops-and-if-else-statements-a05e06e22b76
Comparing JavaScript and Python: Loops and If-Else Statements | by Thomas Garza | Medium
April 5, 2020 - In Python, a for in loop is used to iterate over strings, lists , or dictionaries (please see previous blog post for examples of lists and dictionaries). The for keyword is followed by a variable in iterable statement (no parentheses), which ...
Runestone Academy
runestone.academy › ns › books › published › JS4Python › TheBasics › loops.html
2.5. Loops and Iteration — JavaScript 4 Python Programmers
To be clear in the example above, the loop variable i is an index variable that you use to index into the original array. To iterate over the characters in a string in JavaScript do the following: String t = "Hello World"; for (let c of t) { writeln(c); } To iterate over the elements in an array in JavaScript: var data = [3, 7, 2, 9, 1, 11]; var sum = 0; data.forEach(function(d){ sum += d; }); writeln(sum); Both Python and JavaScript support the while loop.
Ischurov
ischurov.github.io › pythonvjs › show › loop-for › en
For loop — python-v-js
for loop is used mostly for two goals: · This is the most safe way to process all elements of array. Supported in all versions of JS, there is no possibility to mistakenly include properties that are not indexed elements of a list, see another example
Top answer 1 of 2
6
for loops in Python
It can be easily converted using range() or xrange() function. The xrange() is an iterator version, which means it is more efficient (range() would first create a list you would be iterating through). Its syntax is the following: xrange([start], stop[, step]). See the following:
for y in xrange(0, 128, 1024):
for x in xrange(0, 64, 1024):
# here you have x and y
Note
But I hope you have noticed, that due to the fact, that you are incrementing y and x with each respective loop by 1024, you will actually receive something similar to this:
var y = 0;
var x = 0;
or, in Python:
x = 0
y = 0
Anyway, it is just additional note about the code you have given as example.
2 of 2
6
Your code will only perform one iteration in each loop, so you don't even need a loop:
y = 0
x = 0
# do whatever with x and y here
In general, you can use range([start], stop[, step]) [docs] to simulate such a for loop.
For example:
for(var i = 0; i < 10; i += 2)
becomes
for i in range(0, 10, 2)
Medium
medium.com › @ksaquib › the-ultimate-guide-to-for-loops-in-java-javascript-and-python-e16746d37398
The Ultimate Guide to For Loops in Java, JavaScript, and Python | by Saquib Khan | Medium
March 5, 2024 - For loops are fundamental constructs in programming, allowing us to iterate over collections, perform tasks repeatedly, and control the flow of our code. In this comprehensive guide, we’ll explore all types of for loops in three popular programming languages: Java, JavaScript, and Python.
W3Schools
w3schools.com › js › js_loop_for.asp
JavaScript for Loop
When let is used to declare the i variable in a loop, the i variable will only be visible within the loop. ... If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: sales@w3schools.com · If you want to report an error, or if you want to make a suggestion, send us an e-mail: help@w3schools.com · HTML Tutorial CSS Tutorial JavaScript Tutorial How To Tutorial SQL Tutorial Python Tutorial W3.CSS Tutorial Bootstrap Tutorial PHP Tutorial Java Tutorial C++ Tutorial jQuery Tutorial
IBM
ibm.com › reference › python › for-loop
What is a for loop in python? | IBM
November 21, 2025 - Other programming languages also implement for loops, but their syntax and capabilities can vary. Languages like C and Java use a more traditional approach, where the loop is controlled by initializing a variable, setting a loop continuation condition and defining the iteration step. This structure offers fine control over the loop but can be more verbose compared to Python's approach. JavaScript, similar to Python, provides a more streamlined way to iterate through objects like arrays and array-like objects.
Learn Python
learnpython.org › en › Loops
Loops - Learn Python - Free Interactive Python Tutorial
When the loop condition of "for" or "while" statement fails then code part in "else" is executed. If a break statement is executed inside the for loop then the "else" part is skipped.
Hellogirish
hellogirish.com › blog › js-vs-python-loops
JS vs Python: loops - HelloGirish - Girish Gupta
June 22, 2024 - My collection of important Javascript concepts, tip and tricks ... Sr. Software Engineer - ReactJS & React NativeExplore1/2/2020 · Sr. Software Engineer - React Native & ReactJsExplore1/9/2018 ... A complete overview of ReactMemo. ... Girish played an instrumental role in several successful platform releases at Wadhwani Foundation. He is a constant learner who actively seeks out for ...
Trey Hunner
treyhunner.com › 2016 › 04 › how-to-loop-with-indexes-in-python
How to loop with indexes in Python
This JavaScript loop looks nearly identical in C/C++ and Java. ... Now let’s talk about loops in Python. First we’ll look at two slightly more familiar looping methods and then we’ll look at the idiomatic way to loop in Python. If we wanted to mimic the behavior of our traditional C-style for ...
Reddit
reddit.com › r/learnprogramming › for loop in python and for loop in java: differences
r/learnprogramming on Reddit: for loop in Python and for loop in Java: differences
December 21, 2022 - Python has had for-each iteration since before Java was created, afaik — it's present in the earliest online docs: 1.7 documentation from 1996. If you need the flexibility of a 'traditional' for-loop in Python, you can use while.
Programiz
programiz.com › javascript › for-loop
JavaScript for loop (with Examples)
In this example, we used the for loop to print "Hello, world!" three times to the console. ... Once an iteration of the loop is completed, the condition is evaluated again. The process continues until the condition is false. To learn more about the condition, visit JavaScript Comparison and Logical Operators.
Codecademy
codecademy.com › forum_questions › 537b52a7631fe91943001bf7
For loops VS. while loops in JS? Confused. | Codecademy
Okay, I will admit, my python bias is messing me up here. Let’s use this lesson’s example of for(x=0; x < 4; x++) as an example of my confusion. When I see the second part (x <4) of the for loop, I read it as “while x is less than 4.” So… how is this different than a while loop?
Mozilla
developer.mozilla.org › en-US › docs › Web › JavaScript › Guide › Loops_and_iteration
Loops and iteration - JavaScript - MDN Web Docs - Mozilla
A for loop repeats until a specified condition evaluates to false. The JavaScript for loop is similar to the Java and C for loop. ... The initializing expression initialization, if any, is executed. This expression usually initializes one or more loop counters, but the syntax allows an expression ...
CodeHS
codehs.com › tutorial › 12923
Tutorial: For Loops in Python | CodeHS
Learn the basics of for loops in Python.
Python.org
discuss.python.org › python help
Can someone please help a beginner with a loop? - Python Help - Discussions on Python.org
March 24, 2023 - Hi everyone, I am a beginner with coding in general, and learning an online course. We have a task to use a “for” loop to count spaces (" ") in a given string. I wrote a code that returns the right answer for one spac…
Simplilearn
simplilearn.com › home › resources › software development › your ultimate python tutorial for beginners › python for loops - comprehensive guide
Python For Loops - Comprehensive Guide
January 30, 2025 - Learn how to use the 'for loop' in Python with examples. Understand syntax and practical applications for iteration in Python programming.
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freeCodeCamp
freecodecamp.org › news › python-for-loop-example-how-to-write-loops-in-python
Python For Loop Example – How to Write Loops in Python
April 26, 2022 - lang_list = ["Python", "JavaScript", "PHP", "Rust", "Solidity", "Assembly"] for lang in lang_list: print(lang, end=" ") # Output: Python JavaScript PHP Rust Solidity Assembly · A tuple is an iterable data type in Python, so you can write a for loop to print the items in it.