Sunday, September 22, 2019
JavaScript Control Statements:
JavaScript control statements are used to manage the flow of a program by making decisions and repeating actions based on conditions. The primary control statements in JavaScript include:
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| JavaScript Control Statements |
1. if Statement:
- The `if` statement is used to execute a block of code if a specified condition evaluates to true.
javascript
if (condition) {
// Code to be executed if the condition is true
}
2. if-else Statement:
- The `if-else` statement is used to execute one block of code if a condition is true and another block if the condition is false.
javascript
if (condition) {
// Code to be executed if the condition is true
} else {
// Code to be executed if the condition is false
}
3. if-else if-else Statement:
- This statement allows you to test multiple conditions and execute different blocks of code based on which condition is true.
javascript
if (condition1) {
// Code to be executed if condition1 is true
} else if (condition2) {
// Code to be executed if condition2 is true
} else {
// Code to be executed if none of the conditions are true
}
4. switch Statement:
- The `switch` statement is used to perform different actions based on different conditions.
javascript
switch (expression) {
case value1:
// Code to be executed if expression matches value1
break;
case value2:
// Code to be executed if expression matches value2
break;
default:
// Code to be executed if none of the cases match
}
5. for Loop:
- The `for` loop is used to iterate over a block of code a specified number of times.
javascript
for (initialization; condition; iteration) {
// Code to be executed in each iteration
}
6. while Loop:
- The `while` loop is used to repeatedly execute a block of code as long as a specified condition is true.
javascript
while (condition) {
// Code to be executed while the condition is true
}
7. do-while Loop:
- The `do-while` loop is similar to the `while` loop, but it ensures that the code block is executed at least once before checking the condition.
javascript
do {
// Code to be executed at least once
} while (condition);
8. for...in Loop:
- The `for...in` loop is used to iterate over the properties of an object.
javascript
for (variable in object) {
// Code to be executed for each property of the object
}
9. for...of Loop:
- The `for...of` loop is used to iterate over the values of an iterable object (arrays, strings, etc.).
javascript
for (variable of iterable) {
// Code to be executed for each value of the iterable
}
These control statements provide the foundation for managing program flow and implementing various logic structures in JavaScript. They are essential for creating dynamic and responsive applications.