is NULL code example

Example 1: sql not null

SELECT column_name FROM table_name 
WHERE column_name IS NOT NULL;

Example 2: javascript check for null variables

var myVar=null;

if(myVar === null){
    //I am null;
}

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

Example 3: how to check if a column is null in sql

SELECT column_name FROM table_name 
WHERE column_name IS NULL;

Example 4: Null check

function exists (value) {
  return x != null ? Promise.resolve(value) : Promise.reject(`Invalid value: ${value}`)
}