Hi Friends đź‘‹,

Welcome To Infinitbility! ❤️

To check array is undefined in typeScript, use if...else statement it will handle all falsy value like undefined, null, empty and etc.

Let’s see short example to use if...else with array to check array is undefined in typeScript.

if(array){

}

Today, I’m going to show you How do I check array is undefined in typeScript, as above mentioned, I’m going to use the above-mentioned if...else statement.

Let’s start today’s tutorial how do you check array is undefined in typeScript?

TypeScript check array is undefined example

Here, we will take string variable with some data and use if...else statement to check array is undefined.

let arr: Array<string> | undefined;

if(arr && arr.length){
  console.log("arr is defined")
} else {
  console.log("arr is undefined")
}

// You can also check specific conditions like a string is undefined or not

if(arr == undefined){
  console.log("arr is undefined")
} else {
  console.log("arr is defined")
}

I hope it helps you, All the best đź‘Ť.