Solve - Unsyntactic break Error in JavaScript

Solving - Unsyntactic break Error in JavaScript #

The "Unsyntactic break" error occurs when we try to use a break statement outside of a for loop, or inside of a function in the for loop.

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let arr = ['a', 'b', 'c'];

arr.forEach(element => {
  if (element === 'b') {
    break // 👉️ SyntaxError: Unsyntactic break
  }
  console.log('test');
});

The code snippet above causes the error, because we try to use the break statement in a function.

To solve the "Unsyntactic break" error in JavaScript:

• Only use break statements in loop that support the break keyword.
• Throw an error in a try/catch block to break out of the loop if you're in a function and can't use the break statement.

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let arr = ['a', 'b', 'c'];

const BreakError = {};

try {
  arr.forEach(element => {
    if (element === 'b') {
      throw BreakError;
    }
    console.log(element); // 👉️ a
  });
} catch (err) {
  if (err !== BreakError) throw err;
}

In the code snippet we throw an error to break out of the iteration. We can't use the break keyword inside a function, so we wrap the function in a try/catch block and throw an error to exit when we need to.

We can use the break statement in the following scenarios:

• basic for loops
• for ... of loops
• for ... in loops
• while loops
• switch statements

If you're using a forEach loop and trying to use a break statement, try using a for ... of loop instead. You can use the break keyword in a for ... of loop.

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let arr = ['a', 'b', 'c'];

for (const element of arr) {
  if (element === 'b') {
    break;
  }
  console.log(element) // 👉️ a
}