JavaScript Boolean if statement for any truthy value of booleanValue including true, any non-zero number, any non-empty string value, any object or array reference.
if (booleanValue)On the other hand:
if (booleanValue === true)
This will only satisfy the if condition if booleanValue is exactly equal to true. No other truthy value will satisfy it.
If you write: if(x === true) , It will be true for only x = true
If you write: if(x) , it will be true for any x that is not: ” (empty string), false, null, undefined, 0, NaN.
if (condition) {
// code to be executed if condition is true
} else {
// code to be executed if condition is false
}
In this structure:
- The
conditionis an expression that evaluates to eithertrueorfalse. - If the
conditionevaluates totrue, the code block inside theifstatement is executed. - If the
conditionevaluates tofalse, the code block inside theelsestatement (if provided) is executed.
JavaScript Boolean if
Simple example code.
<!DOCTYPE html>
<html>
<body>
<script>
var booleanValue = true;
if(booleanValue === true){
console.log("Boolean === true");
}
if(booleanValue){
console.log("true");
}
</script>
</body>
</html>Output:
You can also have more complex conditions using logical operators like && (AND), || (OR), and ! (NOT) to combine multiple conditions. For example:
var x = 10;
var y = 5;
if (x > 5 && y > 2) {
console.log("Both conditions are true.");
} else {
console.log("At least one condition is false.");
}
In this case, it prints “Both conditions are true.” because both conditions x > 5 and y > 2 are true.
The purpose of: “if(boolean) return;” in Javascript
return; with no value is equivalent to return undefined;. But it’s usually used in functions that aren’t expected to return a value, so it just means “exit the function now”.
So that code is equivalent to:
if (boolean) {
return undefined;
}How to check if the type is Boolean using JavaScript
Answer: Use the typeof operator to check if a value is of boolean type.
(typeof variable === 'boolean')The typeof operator returns a string that indicates the type of a value. If the value is a boolean, the string "boolean" is returned.
const bool = true;
if (typeof bool === 'boolean') {
console.log('✅ type is boolean');
} else {
console.log('⛔️ type is NOT boolean');
}Do comment if you have any doubts or suggestions on this Js Boolean topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version