1. Introduction
The for
loop is a control flow statement in JavaScript that allows you to repeatedly execute a block of code based on a specified condition. It is commonly used when you know the number of iterations required in advance.
2. Syntax
The syntax for a for
loop in JavaScript is as follows:
javascriptfor (initialization; condition; iteration) {
// Code to be executed in each iteration
}
- Initialization: It is an expression that initializes the loop counter. It is executed before the loop starts.
- Condition: It defines the condition for the loop to continue iterating. If the condition evaluates to
true
, the loop continues; otherwise, it exits. - Iteration: It specifies the action to be performed after each iteration. It is executed at the end of each iteration.
3. Example
Let's consider an example where we want to print the numbers from 1 to 5 using a for
loop:
javascriptfor (let i = 1; i <= 5; i++) {
console.log(i);
}
4. Explanation
- The
for
loop begins by initializingi
with a value of 1 (let i = 1
). - The condition
i <= 5
is evaluated. If it istrue
, the loop body is executed; otherwise, the loop is terminated. - In each iteration, the code inside the loop body (in this case,
console.log(i)
) is executed. - After executing the loop body, the iteration statement
i++
increments the value ofi
by 1. - The loop continues until the condition
i <= 5
becomesfalse
.
5. Break and Continue Statements
Inside a for
loop, you can use the break
statement to exit the loop prematurely and the continue
statement to skip the current iteration and proceed to the next one.
- The
break
statement can be used to terminate the loop entirely:
javascriptfor (let i = 1; i <= 5; i++) {
if (i === 3) {
break;
}
console.log(i);
}
- The
continue
statement can be used to skip a specific iteration:
javascriptfor (let i = 1; i <= 5; i++) {
if (i === 3) {
continue;
}
console.log(i);
}
6. Conclusion
The for
loop is a fundamental construct in JavaScript that allows you to iterate over a sequence of values. It provides a compact and structured way to perform repetitive tasks. By understanding its syntax and usage, you can leverage the power of loops to efficiently handle various scenarios in your JavaScript programs.
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