Use System.arraycopy() Instead of Loop
ID |
java.loop_arraycopy |
Severity |
low |
Remediation Complexity |
trivial |
Remediation Risk |
low |
Remediation Effort |
low |
Resource |
Efficiency |
Language |
Java |
Tags |
best-practice, efficiency |
Description
Reports for-loops that copy array elements one by one using indexed assignment (e.g., dest[i] = src[i]).
Rationale
Manually copying arrays element-by-element in a loop is significantly slower than using System.arraycopy(), which is implemented as a native memory operation. For large arrays, the performance difference can be substantial.
// Bad - manual element-by-element copy
for (int i = 0; i < source.length; i++) {
dest[i] = source[i];
}Remediation
Use System.arraycopy() or Arrays.copyOf() for array copying.
// Good - native array copy
System.arraycopy(source, 0, dest, 0, source.length);
// Also good
int[] dest = Arrays.copyOf(source, source.length);