Array toString

ID

java.array_tostring

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Reliability

Language

Java

Tags

code-style

Description

Reports calls to toString() on array objects. Arrays do not override Object.toString(), producing output like [I@1a2b3c instead of the array contents.

Rationale

Calling toString() on an array yields the default Object.toString() implementation, which prints the type and hash code — not the elements. This is almost never the intended behavior and is a common source of confusing log output.

// Bad — prints "[I@1a2b3c"
int[] values = {1, 2, 3};
System.out.println(values.toString());

Remediation

Use java.util.Arrays.toString() for one-dimensional arrays or Arrays.deepToString() for multi-dimensional arrays:

// Good — prints "[1, 2, 3]"
System.out.println(Arrays.toString(values));

References