Unused variable¶
ID: rust/unused-variable
Kind: problem
Security severity:
Severity: recommendation
Precision: high
Tags:
- maintainability
- quality
Query suites:
- rust-security-and-quality.qls
Click to see the query in the CodeQL repository
This rule finds variables that are never accessed. Unused variables should be removed to increase readability and avoid confusion.
Recommendation¶
Remove any unused variables.
Example¶
In the following example, there is an unused variable average that is never used:
fn get_sum(values:&[i32]) -> i32 {
let mut sum = 0;
let mut average; // BAD: unused variable
for v in values {
sum += v;
}
return sum;
}
The problem can be fixed simply by removing the variable:
fn get_sum(values:&[i32]) -> i32 {
let mut sum = 0;
for v in values {
sum += v;
}
return sum;
}
References¶
GeeksforGeeks: How to avoid unused Variable warning in Rust?