It's evaluated outside-in, from left to right, as usually.
The assignment expression returns the assigned value.
Copya = a + b - (b = a); // a=10 b=20
a = 10 + b -( b = a); // a=10 b=20
a = 10 + 20 - (b = a); // a=10 b=20
a = 30 - (b = a); // a=10 b=20
a = 30 - (b = 10); // a=10 b=20
a = 30 - (10); // a=10 b=10
a = 30 - 10; // a=10 b=10
a = 20; // a=10 b=10
20; // a=20 b=10
Answer from Bergi on Stack OverflowW3Schools
w3schools.com › js › js_assignment.asp
JavaScript Assignment
If the first value is true, the second value is assigned. let x = true; let y = x &&= 10; Try it Yourself » · let x = false; let y = x &&= 10; Try it Yourself » ... The &&= operator is an ES2020 feature.
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Operators › Assignment
Assignment (=) - JavaScript | MDN
The assignment (=) operator is used to assign a value to a variable or property. The assignment expression itself has a value, which is the assigned value. This allows multiple assignments to be chained in order to assign a single value to multiple variables.
The assignment operator in JavaScript - Stack Overflow
a is getting assigned the value ... was just assigned the value of a... I think that answer is equally as clear as the question ;) ... I believe MDN's page on Operator Precedence contains all the information needed to figure this one out: developer.mozilla.org/en-US/docs/Web/JavaScript/Refere... More on stackoverflow.com
How do i use an assignment operator
Tell us what’s happening: im having a issue with using the assignment operator You should use character twice in your code. 2. You should use the assignment operator to reassign character. 4. Your character variable should have the value “World”. Your code so far // User Editable Region ... More on forum.freecodecamp.org
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March 2, 2025JavaScript OR (||) variable assignment explanation - Stack Overflow
Also, is this technique specific to JavaScript? I know doing something similar in PHP would result in f having a true boolean value, rather than the value of d itself. ... Old question, but regarding PHP, there is a construct you can use: $f=$a or $f=$b or $f=$c; // etc. PHP has both the || operator and the or operator, which do the same job; however or is evaluated after assignment ... More on stackoverflow.com
Logical assignment operators in JavaScript
Does anybody else find this user.id = user.id || 1 More readable than this user.id ||= 1 Maybe it's just because it's new notation for me. Cool nonetheless. More on reddit.com
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August 31, 2020Videos
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JavaScript Beginners Tutorial 8 | Assignment Operators - YouTube
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Assignment Operators | JavaScript For Beginners | JavaScript ...
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JavaScript Assignment Operators Tutorial in Hindi / Urdu - YouTube
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JavaScript tips — The logical or assignment operator ||= - YouTube
GeeksforGeeks
geeksforgeeks.org › javascript › javascript-assignment-operators
JavaScript Assignment Operators - GeeksforGeeks
October 11, 2025 - Assignment operators are used to assign values to variables in JavaScript.
Mozilla
developer.mozilla.org › en-US › docs › Web › JavaScript › Guide › Expressions_and_operators
Expressions and operators - JavaScript | MDN
For example, x++ or ++x. The operator ... — all other operators, like !, typeof, etc. are prefix. An assignment operator assigns a value to its left operand based on the value of its right operand....
TutorialsPoint
tutorialspoint.com › home › javascript › javascript assignment operators
JavaScript Assignment Operators
September 1, 2008 - The assignment operators in JavaScript are used to assign values to the variables. These are binary operators. An assignment operator takes two operands, assigns a value to the left operand based on the value of right operand.
Top answer 1 of 3
2
It's evaluated outside-in, from left to right, as usually.
The assignment expression returns the assigned value.
Copya = a + b - (b = a); // a=10 b=20
a = 10 + b -( b = a); // a=10 b=20
a = 10 + 20 - (b = a); // a=10 b=20
a = 30 - (b = a); // a=10 b=20
a = 30 - (b = 10); // a=10 b=20
a = 30 - (10); // a=10 b=10
a = 30 - 10; // a=10 b=10
a = 20; // a=10 b=10
20; // a=20 b=10
2 of 3
1
Simple explanations below.
1 . We are assigning our initial values:
Copyvar a = 10;
var b = 20;
2 . Here we're saying a is equal to 10+20 - (10). Therefore a is now equal to 20 and b is equal to 10 as it was assigned to be a before we assigned a's new value.
Copya=a+b-(b=a);
3 . Result:
Copyvar a = 10;
var b = 20;
a = a + b - (b = a);
console.log("a = " + a); // a = 20
console.log("b = " + b); // b = 10
Run code snippetEdit code snippet Hide Results Copy to answer Expand
freeCodeCamp
forum.freecodecamp.org › javascript
How do i use an assignment operator - JavaScript - The freeCodeCamp Forum
March 2, 2025 - Tell us what’s happening: im having a issue with using the assignment operator You should use character twice in your code. 2. You should use the assignment operator to reassign character. 4. Your character variable should have the value “World”. Your code so far // User Editable Region let programmer = "character"; programmer = "World"; // User Editable Region Your browser information: User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome...
Medium
medium.com › @nicholas007 › javascript-assignment-operators-bdb51275699d
JavaScript Assignment Operators. Assignment operators are fundamental to… | by Nicholas | Medium
November 20, 2025 - Here’s something important: the assignment operator not only assigns a value but also returns that value. ... This return behavior enables some interesting patterns, as we’ll see next. Unlike most operators in JavaScript (which evaluate left-to-right), the assignment operator has right-to-left associativity.
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Operators › Logical_OR_assignment
Logical OR assignment (||=) - JavaScript | MDN
July 8, 2025 - No assignment is performed if the left-hand side is not falsy, due to short-circuiting of the logical OR operator. For example, the following does not throw an error, despite x being const: ... const x = { get value() { return 1; }, set value(v) { console.log("Setter called"); }, }; x.value ||= 2; In fact, if x is not falsy, y is not evaluated at all.
HCL Software
help.hcl-software.com › dom_designer › 9.0.1 › reference › r_wpdr_elements_operators_assignment_r.html
Assignment operators (JavaScript)
An assignment operator assigns a value to its left operand based on the value of its right operand. The basic assignment operator is equal (=). The other assignment operators are shorthand for another operation plus the assignment.
W3Schools
w3schools.com › jsref › jsref_oper_assignment.asp
JavaScript Assignment Operators
Assignment operators assign values to JavaScript variables. Given that x = 10 and y = 5, the table below explains the assignment operators: The ??= operator above is an Assignment Operator (nullish assignment).
Scaler
scaler.com › home › topics › javascript assignment operators
JavaScript Assignment Operators - Scaler Topics
March 18, 2024 - Assignment operator in js is an element that helps in the process of assigning values to variables. It is a symbol or a combination of symbols used to assign a value on the right side to a variable on the left side.
Sololearn
sololearn.com › en › Discuss › 2145585 › what-is-assignment-operators-in-javascript-and-what-is-work-and-what-it-s-used-in-javascript
What is Assignment Operators in JavaScript and what is work and what it's used in JavaScript? | Sololearn: Learn to code for FREE!
January 25, 2020 - [let userName;] (a box was brought ... point, javascript will give you the answer: "undefined". to assign a value to a variable, use the "= " assignment operator....
JavaScript Tutorial
javascripttutorial.net › home › javascript tutorial › javascript assignment operators
JavaScript Assignment Operators
November 13, 2024 - In JavaScript, an assignment operator (=) assigns a value to a variable.
LabEx
labex.io › tutorials › html-explore-assignment-operators-in-javascript-451048
Explore Assignment Operators in JavaScript | LabEx
Assignment Operator Demonstration Initial Value: 10 After Basic Assignment (=): 20 After Addition Assignment (+=): 25 After Subtraction Assignment (-=): 22 After Multiplication Assignment (*=): 44 After Division Assignment (/=): 11 · In this lab, participants explore JavaScript assignment operators through a hands-on HTML and JavaScript exercise.
Top answer 1 of 12
251
See short-circuit evaluation for the explanation. It's a common way of implementing these operators; it is not unique to JavaScript.
2 of 12
240
This is made to assign a default value, in this case the value of y, if the x variable is falsy.
The boolean operators in JavaScript can return an operand, and not always a boolean result as in other languages.
The Logical OR operator (||) returns the value of its second operand, if the first one is falsy, otherwise the value of the first operand is returned.
For example:
"foo" || "bar"; // returns "foo"
false || "bar"; // returns "bar"
Falsy values are those who coerce to false when used in boolean context, and they are 0, null, undefined, an empty string, NaN and of course false.
Tabnine
tabnine.com › home › how to use the assignment operator in javascript
How to Use the Assignment Operator in JavaScript - Tabnine
July 25, 2024 - The Assignment operator is used to assign a value to a variable. Assignment (=) The assignment operator simply assigns the value of the right operand to the variable specified by the left operand. let y = 5; In the example above, let y is assigned ...
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Operators › Logical_AND_assignment
Logical AND assignment (&&=) - JavaScript | MDN
No assignment is performed if the left-hand side is not truthy, due to short-circuiting of the logical AND operator. For example, the following does not throw an error, despite x being const: ... const x = { get value() { return 0; }, set value(v) { console.log("Setter called"); }, }; x.value &&= 2; In fact, if x is not truthy, y is not evaluated at all.
DEV Community
dev.to › coder_studios › understanding-assignment-operators-in-javascript-from-basics-to-advanced-concepts-34e0
Understanding Assignment Operators in JavaScript: From Basics to Advanced Concepts - DEV Community
March 24, 2025 - The basic assignment operator is =, which assigns the value on the right to the variable on the left. Why: They are fundamental to programming because they allow you to store and manipulate data in your applications.
D-libro
d-libro.com › javascript coding with ai › assignment operators
Mastering Assignment Operators in JavaScript: A Complete Guide - Topic
January 13, 2025 - The basic assignment operator is the simplest one. It is used to assign the value on the right-hand side to the variable on the left-hand side. ... This is the most commonly used assignment operator and is foundational for all JavaScript code.