What distinguishes directly assigning a processed value to a variable from first assigning without processing and then processing using the && operator?

Recently, I came across a function that takes a string parameter and then carries out some operations on it. Here is an example of how it was implemented:

const val = this.searchParam && this.searchParam.trim().toLowerCase();

This made me wonder why the processed string wasn't assigned directly like this:

const val = this.searchParam.trim().toLowerCase();

To investigate further, I tested both approaches in JS Bin and found that the result was identical.

Can anyone clarify the specific purpose of the "&&" operator used in this context?

javascript

Answer №1

Looking at the code snippet below, the outcome is different for each scenario: 

searchParam = undefined

console.log(searchParam && searchParam.trim().toLowerCase());
console.log(searchParam.trim().toLowerCase());

Hence, it can be concluded that the final result is not identical.

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