String length() and trim() Commands

You can get the length of a Strings using the length() command, or eliminate extra characters using the trim() command. This example shows you how to use both commands.

Step 1: What You Need?

1 x Arduino Board ( Arduino UNO R3 used in this tutorial.)
1 x USB Type-B Cable 


Optional 

Arduino Uno R3 Acrylic Transparent Casing

Arduino Compatible UNO Ultimate Starter Kit / Learning Kit

Don't have components? Don't worry. Just click the component's name. 

Step 2: Build Your Circuit.

There is no circuit for this example, though your board must be connected to your computer via USB and the serial monitor window of the Arduino Software (IDE) should be open.

Step 3: Upload The Code.

1. Select the Arduino board type: Select Tools >> Board >> Select your correct Arduino board used.

2. Find the port number by accessing device manager on Windows. See the section Port (COM&LPT) and look for an open port named "Arduino Uno (COMxx)". If you are using a different board, you will find a name accordingly. What matters is the xx in COMxx part. In my case, it's COM3. So my port number is 3.

Select the right port: Tools >> Port >> Select the port number.

3. You can find this code in the example of Arduino IDE.

Select File >> Examples >> 08. Strings >> StringLength or StringLengthTrim

Click press the "upload" button (see the button with right arrow mark).

The example below shows a String with whitespace, before and after trimming:

trim() is useful for when you know there are extraneous whitespace characters on the beginning or the end of a String and you want to get rid of them. Whitespace refers to characters that take space but aren't seen. It includes the single space (ASCII 32), tab (ASCII 9), vertical tab (ASCII 11), form feed (ASCII 12), carriage return (ASCII 13), or newline (ASCII 10). 

Download:

Arduino IDE

Sources:https://www.arduino.cc/en/Tutorial/StringLengthTrim

08.Strings library StringLength StringLengthTrim