Page 191 - Web Applications (803) Class 12
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JavaScript differs from other languages like Java as there is no scope for blocks. However, functions have scope.
Therefore, the entire function will be able to see a variable that is defined using the var keyword in a compound
expression (such as inside an if control structure).
Lab Assignment ‘n Activity Interdisciplinary
Write JavaScript code for the following:
Initialise variables for principal, rate and time. Calculate and display simple interest.
Initialise a string variable with your name. Find the length of this string. Then display the square of
that number.
Initialise variable for length, breadth and height of a cuboid. Calculate and display the
volume of a cuboid. (Hint: Volume = length*breadth*height)
Initialise variable for radius of a circle. Calculate and display the area and circumference of
the circle.
3.7 CONTROL STRUCTURES
If and else, as detailed below, support conditional statements.
• If the stated condition is true, specify a block of code to be executed; otherwise, specify a block of code to
be performed if the same condition is false.
• If the first condition is false, if (statement) specifies a new condition to test. (else if….)
• The switch (statement) specifies a number of different code blocks to be performed.
Let us now understand the working of the if….else statements in JavaScript.
Syntax:
if (condition) {
// block of code to be executed when the condition is true
} else {
// block of code to be executed when the condition is false
}
Web Scripting—JavaScript 189

