Control statements are used
to control and execute the statements based on certain conditions or
repeat a group of statements until certain specified conditions are met
There are different types
of if statements in javaScript.
·
if
statement
·
if-else
statement
·
nested
if statement
·
if-else-if
ladder
if Statement:
if statement checks the
condition. It is executed if condition is true.
Syntax:
if(condition)
{
//statement
}
Example:
<script>
var x=50;
if(x>40){
document.write("it
is greater than 40");
}
</script>
if-else Statement
If-else statement checks
the condition. It executes if condition is true otherwise it comes to else
block and else block will be executed.
Syntax:
if(condition)
{
//statement
}
else
{
//statement
}
Example:
<script>
var x=30;
if(x>0)
{
document.write("+ve
number");
}
else{
document.write("-ve
number");
}
</script>
If-else-if ladder Statement
if-else-if ladder statement
executes one condition from multiple conditions.It will check the conditions
one by one ,if the condition is true then print the output otherwise it comes
to else block and else block will be executed.
Syntax:
if(condition1){
/ /statement
}
else if(condition2){
/ /statement
}
else if(condition2){
//statement
}
else if(condition3){
}
else if(condition3){
//statement
}
...........................
}
...........................
else{
//statement
//statement
}
Example:
<script>
<script>
var x=30;
if(x>0){
document.write("+ve
number");
}
else
if(x<0){
document.write("-ve
number");
}
else
if(x==0){
document.write("zero");
}
else
{
document.write("please
enter a number");
}
</script>
switch
switch statement executes
one statement from multiple conditions. It will check the conditions one by
one. If it finds true, it will print the output otherwise it comes to default
and default statement will be executed. It is just like if-else-if ladder
Syntax:
switch(expression){
case value1:
//statement
break;
case value2:
//statement
break;
......
default:
//statement
}
Example:
<script>
var
month =parseInt(prompt("Enter month(1-12)"));
switch(month)
{
case 1:
alert("31 days");
break;
case 2:
alert("28/29 days");
break;
case 3:
alert("31 days");
break;
case 4:
alert("30 days");
break;
case 5:
alert("31 days");
break;
case 6:
alert("30 days");
break;
case 7:
alert("31 days");
break;
case 8:
alert("31 days");
break;
case 9:
alert("30 days");
break;
case 10:
alert("31 days");
break;
case 11:
alert("30 days");
break;
case 12:
alert("31 days");
break;
default:
alert("Invalid month! Please enter month number between 1-12");
}
</script>
Python is an open-source, high level, interpreted programming language which offers great opportunities for object-oriented programming. Choosing a python training program from Red Prism Group, which is best training institute for python in noida.
ReplyDelete