javascript check if undefined or null or empty code example

Example 1: javascript not null

if (variable !== null) {
  console.log("Var is NOT null");
}

Example 2: javascript check if undefined or null

if( typeof myVar === 'undefined' || myVar === null ){
    // myVar is undefined or null
}

Example 3: javascript is not null

if(data !== null && data !== '') {
   // do something
}

Example 4: javascript check if not null

//Even if the value is 0, this will execute. 

if (myVar !== null) {...}

//If you don't want it to execute when it's 0, then set it as

if (myVar) {...}

//This will return false if var value is 0.

Example 5: javascript check if undefined or null or empty string

// simple check do the job
if (myString) {
 // comes here either myString is not null,
 // or myString is not undefined,
 // or myString is not '' (empty).
}

Example 6: javascript check if undefined or null

// simple check do the job
if (myVar) {
 // comes here either myVar is not null,
 // or myVar is not undefined,
 // or myVar is not '' (empty string).
}