The difference between = and == in js

The = and == operators in JavaScript serve different purposes. = is the assignment operator, used to assign a value to a variable, while == is the comparison operator, used to compare two values ​​for equality, regardless of type. In general, it is recommended to use the strict equality operator === because it compares both values ​​and types to avoid unexpected equality comparison results.

The difference between = and == in JavaScript

In JavaScript, = and == are two different operators used for different purposes.

Assignment Operator (=)

= The operator is used to assign a value to a variable or property. For example:

let x = 10;
const y = "Hello";

The above code assigns the value 10 to the variable x, and assigns the string "Hello" to the constant y.

Comparison Operator (==)

== The operator is used to compare whether two values ​​are equal. It only compares the value of two values, regardless of type. For example:

console.log(10 == "10"); // true
console.log(false == 0); // true

The above code outputs true, because the values ​​of 10 and "10" are equal, and false and The values ​​of 0 are also equal.

Difference

• = is the assignment operator, used to assign values.
• == is a comparison operator used to compare whether values ​​are equal.
• == does not consider the type, while === compares whether both value and type are equal.

Usage Recommendations

Normally, it is recommended to use the strict equality operator === because it not only compares values; Compare types. This avoids unexpected equality comparison results. For example:

console.log(10 === "10"); // false
console.log(false === 0); // false

The above code outputs false, because 10 and "10" have different types, false and The types of 0 are also different.

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