Label a feature layer based on field value differences in Map Viewer

Summary

In Map Viewer, it is possible to label numeric data in a feature layer by calculating the difference between multiple field values and comparing it with a fixed value using an Arcade expression. This is useful for dynamically highlighting variations within the geographic dataset and quickly identifying patterns, trends, or anomalies.

In this article, the feature layer contains two fields named Income and Expense. Using an Arcade expression, labels are created by calculating the difference between the two field values, and the difference is compared to a fixed value of 5000.

Procedure

1. Open the web map in Map Viewer.
2. On the Settings (light) toolbar, click Labels . Ensure labels are enabled by toggling Enable labels on.
3. In the Label features pane, click Add label class. Under Label field, click Use expression . 
4. In the editor window, configure the expression below.

var <variable1> = $feature.<field_name1>;
var <variable2> = $feature.<field_name2>;
var <variable3> = <value>;                                                                               

if (<variable1> - <variable2> > <variable3>) {
    return "<output1>";
} else if (<variable1> - <variable2> < <variable3>) {
    return "<output2>";
} else {
    return "<output3>";
}

1. Replace <variable1>, <variable2>, and <variable3>with the desired variable names. In this example, income, expense, and budget are used.
2. Replace <field_name1> and <field_name2> with the names of the fields containing the field values. In this example, Income and Expense are used.
3. Replace <value> with a value to be compared with the difference between the two field values. In this example, it is 5,000.
4. Replace <output1>, <output2>, and <output3> with the statements to be displayed as labels. In this example, Above Budget, Below Budget, and On Budget are the statements used.

5. Click Done.

The image below displays the labels with the field value differences on the web map.