What Is JavaScript if-else Statement And How To Use It
Posted by TotalDC
JavaScript if-else statements are used to decide the flow of execution based on different conditions. If a condition is true, you can perform one action and if the condition is false, you can perform another action.
In this article you will learn:
JavaScript If Statement
Syntax:
if (condition)
{
lines of code to be executed if condition is true
}You can use If statement if you want to check only a specific condition.
Try this yourself:
<head>
<title>IF Statments</title>
<script type="text/javascript">
const age = prompt("Please enter your age");
if(age>=18){
console.log("You are an adult <br />");
}
if(age<18){
console.log("You are NOT an adult <br />");
}
</script>
</head>
<body>
</body>
</html>JavaScript If… Else Statement
Syntax:
if (condition)
{
lines of code to be executed if the condition is true
}
else
{
lines of code to be executed if the condition is false
}You can use If….Else statement if you have to check two conditions and execute a different set of codes.
Try this yourself:
<html>
<head>
<title>If...Else Statments</title>
<script type="text/javascript">
// Get the current hours
let hours = new Date().getHours();
if(hours<12){
console.log("Good Morning<br />");
}
else {
console.log("Good Afternoon<br />");
}
</script>
</head>
<body>
</body>
</html>JavaScript If… Else if … Else Statement
Syntax:
if (condition1)
{
lines of code to be executed if condition1 is true
}
else if(condition2)
{
lines of code to be executed if condition2 is true
}
else
{
lines of code to be executed if condition1 is false and condition2 is false
}You can use If….Else If….Else statement if you want to check more than two conditions.
Try this yourself:
<html>
<head>
<script type="text/javascript">
let one = prompt("Enter the first number");
let two = prompt("Enter the second number");
one = parseInt(one);
two = parseInt(two);
if (one == two){
console.log(one + " is equal to " + two + ".");
}
else if (one<two){
console.log(one + " is less than " + two + ".");
}
else {
console.log(one + " is greater than " + two + ".");
}
</script>
</head>
<body>
</body>
</html>
