Conditional statements are used to control how execution proceeds in response to various situations. You can perform one action if the condition is true and another action if the condition is false. Conditional statements are an integral part of computer program logic, decision-making, or process control.
The task we will perform in this article is to use conditional statements on objects. Let’s read this article in depth to understand conditional statements better.
Use if statement
The if statement is the most basic type of conditional expression. If a statement is evaluated to see whether it is true or false, the if statement is only executed if the statement returns true. If the result is wrong, the code block will be ignored.
grammar
The following is the syntax of if statement -
if (condition) {
// return out if condition is true
}
Example
In the example below, we run the script using an if statement to check if the condition is true or false.
<!DOCTYPE html>
<html>
<body style="background-color:#D5F5E3">
<script>
const amount = 1000;
const shirt = 1500;
if (amount <= shirt) {
document.write("Insufficient Amount!");
}
</script>
</body>
</html>
When the script executes, it generates an output containing the text obtained when the conditions used in the script pass, and that text is displayed on the web page.
Use switch statement
Use the switch statement to execute a piece of code according to various scenarios. A switch statement is part of a "conditional" statement in JavaScript and is used to perform various actions based on certain conditions. To select which of many blocks of code will be executed, use switches.
grammar
The following is the syntax of the switch statement -
switch(expression) {
case a:
break;
case b:
break;
default:
}
Example
Consider the following example, we are running a script to execute a block of code using a switch statement -
<!DOCTYPE html>
<html>
<body style="background-color:#E8DAEF">
<script>
const d = new Date();
switch (d) {
case 1:
document.write("Monday")
break
case 2:
document.write("Tuesday")
break
case 3:
document.write("Wednesday")
break
default:
document.write("Waiting For The Weekend.!")
}
</script>
</body>
</html>
When the above script is run, an output window will appear, displaying the information obtained by the switch statement conditions displayed on the web page.
Use if else statement
The if statement causes a block to be executed if the condition is true. If the condition is false, nothing happens. However, you can use an if else statement to run the sentence when the condition is false.
grammar
The following is the syntax of if else statement -
if( condition ) {
//statement
} else {
// statement
}
Example
Execute the following code and observe how we execute the conditional "if else" statement in the script.
<!DOCTYPE html>
<html>
<body style="background-color:#D5F5E3">
<script>
let age = 20;
if (age >18) {
document.write('You Are Eligible For Vote.');
} else {
document.write('You Are Not Eligible For Vote.');
}
</script>
</body>
</html>
When the script executes, it will generate an output consisting of the text obtained from the conditions used in the script and display it on the web page.
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