if variable is not defined javascript code example
Example 1: js if not undefined
if (typeof myVar !== "undefined") {
console.log("myVar is DEFINED");
}
Example 2: checking if var is not defined js
if(typeof x !== 'undefined'){
alert("Variable x is defined.");
}
Example 3: How can I check whether a variable is defined in Node Js
if (query){
doStuff();
}