# Replace Equality Check with isEmpty()
# Properties
| Property | Value |
|---|---|
| Rule ID | UseIsEmptyOnCollections |
| First seen in jSparrow version | 2.0.2 |
| Minimum Java version | 6 |
| Remediation cost | 2 min |
| Links | S1155 |
# Description
This rule replaces comparisons of length() or size() with 0 with a call to isEmpty(). Any occurrences of such a comparison will be replaced, regardless of surrounding control structure.
# Benefits
The time complexity of any isEmpty() method implementation should be O(1) whereas some implementations of size() can be O(n). Thus, using this rule provides performance benefits.
# Code Changes
# size, length
Pre
Map<String, String> m = new HashMap<>();
if(m.size() == 0);
String s = "";
if(s.length() == 0);
Post
Map<String, String> m = new HashMap<>();
if(m.isEmpty());
String s = "";
if(s.isEmpty());
Automatic Application of This Rule
The automatic application of this rule is supported in the following jSparrow versions:
# Tags
1
You & jSparrow
