How to Break Out of a Foreach Loop

Short circuit Array.forEach like calling break

There's no built-in ability to break in forEach. To interrupt execution you would have to throw an exception of some sort. eg.

var BreakException = {};
try {  [1, 2, 3].forEach(function(el) {    console.log(el);    if (el === 2) throw BreakException;  });} catch (e) {  if (e !== BreakException) throw e;}

How to exit out of javascript forEach loop

According to the MDN web docs:

There is no way to stop or break a forEach() loop other than by
throwing an exception.

Reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach

how to stop Javascript forEach?

You can't break from a forEach. I can think of three ways to fake it, though.

1. The Ugly Way: pass a second argument to forEach to use as context, and store a boolean in there, then use an if. This looks awful.

2. The Controversial Way: surround the whole thing in a try-catch block and throw an exception when you want to break. This looks pretty bad and may affect performance, but can be encapsulated.

3. The Fun Way: use every().

['a', 'b', 'c'].every(function(element, index) {
  // Do your thing, then:
  if (you_want_to_break) return false
  else return true
})

You can use some() instead, if you'd rather return true to break.

How to break ForEach Loop in TypeScript

It is not possible to break from forEach() normally.

Alternatively you can use Array.every() because you wish to return false while breaking the loop.

If you want to return true, then you can use Array.some()

this.tab.committee.ratings.every(element => {

  const _fo = this.isEmptyOrNull(element.ratings.finalOutcome.finaloutlook);
  const _foreign = this.isEmptyOrNull(element.ratings.finalOutcome.foreign);
  const _local = this.isEmptyOrNull(element.ratings.finalOutcome.local);
  const _tally = element.ratings.finalOutcome.voteTally.maj + element.ratings.finalOutcome.voteTally.dis;

  if (_fo == false && _foreign == false && _local == false) {
    if (_tally > 0) {
      **return count = false;**
    }
  } else {
    if (_tally < 0) {
      **return count = false;**
    }
  }
});

Breaking out of an inner foreach loop

If you need to be able to break an iteration, use .every() instead of .forEach():

someArray.every(function(element) {
  if (timeToStop(element)) // or whatever
    return false;
  // do stuff
  // ...
  return true; // keep iterating
});

You could flip the true/false logic and use .some() instead; same basic idea.

How to break out from foreach loop in javascript

Use a for loop instead of .forEach()

var myObj = [{"a": "1","b": null},{"a": "2","b": 5}]
var result = false

for(var call of myObj) {
    console.log(call)
    
    var a = call['a'], b = call['b']
     
    if(a == null || b == null) {
        result = false
        break
    }
}

break out of if and foreach

if is not a loop structure, so you cannot "break out of it".

You can, however, break out of the foreach by simply calling break. In your example it has the desired effect:

$device = "wanted";
foreach($equipxml as $equip) {
    $current_device = $equip->xpath("name");
    if ( $current_device[0] == $device ) {
        // found a match in the file            
        $nodeid = $equip->id;

        // will leave the foreach loop immediately and also the if statement
        break;
        some_function(); // never reached!
    }
    another_function();  // not executed after match/break
}

Just for completeness for others who stumble upon this question looking for an answer..

break takes an optional argument, which defines how many loop structures it should break. Example:

foreach (['1','2','3'] as $a) {
    echo "$a ";
    foreach (['3','2','1'] as $b) {
        echo "$b ";
        if ($a == $b) { 
            break 2;  // this will break both foreach loops
        }
    }
    echo ". ";  // never reached!
}
echo "!";

Resulting output:

1 3 2 1 !

How to exit out of ForEach loop once condition is met

It's impossible to break forEach loop.
(unless you want to use exceptions, but it's not recommended)
There are two options to solve the problem:

Change the loop type to for, and not forEach, and then use the break statement.
Use a flag to know that the email was sent:


function sendEiEmail() {
    var ss = SpreadsheetApp.getActive().getSheetByName('Attendance Narrative Generator');
    var arr = ss.getRange(7, 1, 10, 1).getValues(); //Get all values from sheet
    var htmlBodyNoLate = HtmlService.createTemplateFromFile("AttendanceNoLate").evaluate().getContent();
    var htmlBodyLate = HtmlService.createTemplateFromFile("AttendanceLate").evaluate().getContent();

    var isEmailSent = false;
    arr.forEach(function (res) {
        if (isEmailSent == false) {
            if (res == 'Late') {
                MailApp.sendEmail({
                    to: Session.getActiveUser().getEmail(),
                    subject: `Attendance Infractions Narrative - ${firstName} ${lastName} #${employeeEID}`,
                    htmlBody: htmlBodyLate,
                });
                isEmailSent = true;
            } else {
                MailApp.sendEmail({
                    to: Session.getActiveUser().getEmail(),
                    subject: `Attendance Infractions Narrative - ${firstName} ${lastName} #${employeeEID}`,
                    htmlBody: htmlBodyNoLate,
                });
                isEmailSent = true;
            }
        }

    });
}

How do I exit an Array.forEach loop early?

Rather than using Array.forEach, you can use Array.some (see docs). This function iterates over the elements of the array, checking to see if any element meets a certain condition. If an element is found that meets the condition, the function stops iteration, and returns true. If not, the function returns false. This means that you can also skip the step of initializing conditionMet to false.

Your code can therefore be simplified as:

let conditionMet = numbers.some(number => (number % 3 === 0));