How to Label Continued on Back

Label Statement

The Label Statement is used with the break and continue statements and serves to identify the statement to which the break and continue statements apply.

We'll talk more about the break and continue statements below.

Syntax

                labelname:   statements              

Usage

Without the use of a labeled statement the break statement can only break out of a loop or a switch statement. Using a labeled statement allows break to jump out of any code block.

Example

                foo: {   console.log("This prints:");   break foo;   console.log("This will never print."); } console.log("Because execution jumps to here!") /* output This prints: Because execution jumps to here! */              

When used with a continue statement the labeled statement allows you to skip a loop iteration, the advantage comes from being able to jump out from an inner loop to an outer one when you have nested loop statements. Without the use of a labeled statement you could only jump out of the existing loop iteration to the next iteration of the same loop.

Example

                // without labeled statement, when j==i inner loop jumps to next iteration function test() {   for (var i = 0; i < 3; i++) {     console.log("i=" + i);     for (var j = 0; j < 3; j++) {       if (j === i) {         continue;       }       console.log("j=" + j);     }   } }  /* output i=0 (note j=0 is missing) j=1 j=2 i=1 j=0 (note j=1 is missing) j=2 i=2 j=0 j=1 (note j=2 is missing) */  // using a labeled statement we can jump to the outer (i) loop instead function test() {   outer: for (var i = 0; i < 3; i++) {     console.log("i=" + i);     for (var j = 0; j < 3; j++) {       if (j === i) {         continue outer;       }       console.log("j=" + j);     }   } }  /* i=0 (j only logged when less than i) i=1 j=0 i=2 j=0 j=1 */              

Break statement

The break statement terminates the current loop, switch or label statement and transfers program control to the statement following the terminated statement.

                break;              

If the break statement is used in a labeled statement, the syntax is as follows:

                break labelName;              

Examples

The following function has a break statement that terminates the while loop when i is 3, and then returns the value 3 * x .

                function testBreak(x) {   var i = 0;    while (i < 6) {     if (i == 3) {       break;     }     i += 1;   }    return i * x; }              

Run Code

In the following example, the counter is set up to count from 1 to 99; however, the break statement terminates the loop after 14 counts.

                for (var i = 1; i < 100; i++) {   if (i == 15) {     break;   } }              

Run Code

Continue statement

The continue statement terminates execution of the statements in the current iteration of the current or labeled loop, and continues execution of the loop with the next iteration.

                continue;              

If the continue statement is used in a labeled statement, the syntax is as follows:

                continue labelName;              

In contrast to the break statement, continue does not terminate the execution of the loop entirely; instead:

• In a while loop, it jumps back to the condition.
• In a for loop, it jumps to the update expression.

Examples

The following example shows a while loop that has a continue statement that executes when the value of i is 3. Thus, n takes on the values 1, 3, 7, and 12.

                var i = 0; var n = 0;  while (i < 5) {   i++;    if (i === 3) {     continue;   }    n += i;   console.log (n); }              

Run Code

In the following example, a loop iterates from 1 through 9. The statements between continue and the end of the for body are skipped because of the use of the continue statement together with the expression (i < 5).

                for (var i = 1; i < 10; i++) {     if (i < 5) {         continue;     }     console.log (i); }              

Run Code

---

Learn to code for free. freeCodeCamp's open source curriculum has helped more than 40,000 people get jobs as developers. Get started

sullivansterty.blogspot.com

Source: https://www.freecodecamp.org/news/javascript-loops-label-statement-continue-statement-and-break-statement-explained/

Share this post