Author: John Au-Yeung

Sometimes, we want to export all functions from a file in JavaScript.

In this article, we’ll look at how to export all functions from a file in JavaScript.

How to export all functions from a file in JavaScript?

To export all functions from a file in JavaScript, we can use the export keyword.

For instance, we write

export const foo = () => {
  // ...
};
export const bar = () => {
  // ...
};
export const baz = (value) => {
  // ...
};

to export the foo, bar, and baz functions by adding export before the function expression.

Conclusion

To export all functions from a file in JavaScript, we can use the export keyword.

Sometimes, we want to add ID’s to Google map markers with JavaScript.

In this article, we’ll look at how to add ID’s to Google map markers with JavaScript.

How to add ID’s to Google map markers with JavaScript?

To add ID’s to Google map markers with JavaScript, we can add custom attributes.

For instance, we write

const marker = new google.maps.Marker({
  map,
  position,
  storeId: id,
});

const storeId = marker.get("storeId");

to create a marker with the Marker constructor.

We add the storeId custom attribute.

Then we call marker.get with the attribute name string to get the attribute value.

Conclusion

To add ID’s to Google map markers with JavaScript, we can add custom attributes.

Sometimes, we want to check if input is number or letter JavaScript.

In this article, we’ll look at how to check if input is number or letter JavaScript.

How to check if input is number or letter JavaScript?

To check if input is number or letter JavaScript, we can use the isNaN function.

For instance, we write

const checkInput = () => {
  const x = document.forms.myForm.age.value;
  if (isNaN(x)) {
    alert("Must input numbers");
    return false;
  }
};

to define the checkInput function.

In it, we get the value from the input with name age in the form with name myForm with document.forms.myForm.age.value.

We check if the value isn’t a number with isNaN.

If it’s true, then x isn’t a number.

Conclusion

To check if input is number or letter JavaScript, we can use the isNaN function.

Sometimes, we want to remove x-axis label and text in Chart.js and JavaScript.

In this article, we’ll look at how to remove x-axis label and text in Chart.js and JavaScript.

How to remove x-axis label and text in Chart.js and JavaScript?

To remove x-axis label and text in Chart.js and JavaScript, we can set some properties in options.

In Chart.js 3.x, we write

const chart = new Chart(ctx, {
  //...
  options: {
    scales: {
      x: {
        display: false,
      },
    },
  },
});

to remove x-axis labels and grid chart lines.

We write

const chart = new Chart(ctx, {
  //...
  options: {
    scales: {
      x: {
        ticks: {
          display: false,
        },
      },
    },
  },
});

to remove only x-axis labels.

In Chart.js 2.x, we write

const chart = new Chart(ctx, {
  //...
  options: {
    scales: {
      xAxes: [
        {
          display: false,
        },
      ],
    },
  },
});

to remove x-axis labels and grid chart lines.

We write

const chart = new Chart(ctx, {
  //...
  options: {
    scales: {
      xAxes: [
        {
          ticks: {
            display: false,
          },
        },
      ],
    },
  },
});

to remove only x-axis labels.

Conclusion

To remove x-axis label and text in Chart.js and JavaScript, we can set some properties in options.

Sometimes, we want to use setZoom() after use fitBounds() with Google Maps API V3 with JavaScript.

In this article, we’ll look at how to use setZoom() after use fitBounds() with Google Maps API V3 with JavaScript.

How to use setZoom() after use fitBounds() with Google Maps API V3 with JavaScript?

To use setZoom() after use fitBounds() with Google Maps API V3 with JavaScript, we can use the getZoom and setZoom methods.

For instance, we write

google.maps.event.addListenerOnce(map, "bounds_changed", function (event) {
  if (this.getZoom() > 15) {
    this.setZoom(15);
  }
});

to listen to the bounds_change event on the map with addListenerOnce.

In the event listener, we call getZoom to check of the zoom level is bigger than 15.

If it is, then we call setZoom to set the zoom level to 15.

Conclusion

To use setZoom() after use fitBounds() with Google Maps API V3 with JavaScript, we can use the getZoom and setZoom methods.