This operator is represented by x &&= y, and it is called the logical AND assignment operator. It assigns the value of y into x only if x is a truthy value.
We use this operator x &&= y like this. Now break this expression into two parts, x && (x = y). If the value of x is true, then the statement (x = y) executes, and the value of y gets stored into x but if the value of x is a falsy value then the statement (x = y) does not get executed.
Syntax :
x &&= y
is equivalent to
x && (x = y)
Example: This example shows the basic use of the Javascript Logical AND assignment(&&=) operator.
<script> let name = {
firstName: "Ram" ,
lastName: "" ,
};
console.log(name.firstName);
// Changing the value using logical
// AND assignment operator
name.firstName &&= "Shyam" ;
// Here the value changed because
// name.firstName is truthy
console.log(name.firstName);
console.log(name.lastName);
// Changing the value using logical
// AND assignment operator
name.lastName &&= "Kumar" ;
// Here the value remains unchanged
// because name.lastName is falsy
console.log(name.lastName);
</script> |
Output :
"Ram" "Shyam" "" ""
Example 2: This example shows the basic use of the Javascript Logical AND assignment(&&=) operator.
< h1 style = "color:green" >
Geeksforgeeks
</ h1 >
< h3 >
Javascript Logical AND assignment(&&=) operator
</ h3 >
< p id = "print_arr" ></ p >
< script >
let arr = [1, 2, "apple", null, undefined, []]
// Replace each truthy values with "gfg"
arr.forEach((item, index)=>{
arr[index] &&= "gfg"
})
document.getElementById("print_arr").innerText = arr.toString();
//console.log(arr)
</ script >
|
Output :
We have a complete list of Javascript Operators, to check those please go through the Javascript Operators Complete Reference article.
Supported Browsers:
- Chrome 85
- Edge 85
- Firefox 79
- Safari 14