1. the first step is to open matlab on our computer and create a variable str =12345+0438+0489 in the command line window; , using the format; When displaying str, you can see that the default format is short, short is a short algebraic expression, and four decimal places are displayed, as shown in the following figure:

2. In the second step, we use "long format; Str "code changes the data display format to long format, as shown in the figure below:

3, the third step through the "format short g; Str "code makes the data display format short and compact, and you can set different display formats of data as required, as shown in the following figure:

4. Step 4: Click Preset on the homepage to set the default display format for creating variables and arrays, as shown in the following figure:

5. Step 5: After entering the preset interface, click Variable to see that the default array variable format is short, as shown in the following figure:

6. Step 6: Click the drop-down list to set the default display format of array variables, and click OK to finish the setting, as shown in the following figure: