undefined null check javascript code example
Example 1: null undefined javascript
Undefined used for unintentionally missing values.
Null used for intentionally missing values.
Example 2: 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 3: 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).
}