useValidForDirection (since v1.0.0)
Diagnostic Category: lint/correctness/useValidForDirection
Sources:
- Same as:
for-direction
Enforce “for” loop update clause moving the counter in the right direction.
A for loop with a stop condition that can never be reached, such as one with a counter that moves in the wrong direction, will run infinitely. While there are occasions when an infinite loop is intended, the convention is to construct such loops as while loops. More typically, an infinite for loop is a bug.
Examples
Section titled ExamplesInvalid
Section titled Invalidfor (var i = 0; i < 10; i--) {}correctness/useValidForDirection.js:1:5 lint/correctness/useValidForDirection ━━━━━━━━━━━━━━━━━━━━━━
✖ The update clause in this loop moves the variable in the wrong direction.
> 1 │ for (var i = 0; i < 10; i--) {
│ ^^^^^^^^^^^^^^^^^^^^^^^^
2 │ }
3 │
for (var i = 10; i >= 0; i++) {}correctness/useValidForDirection.js:1:5 lint/correctness/useValidForDirection ━━━━━━━━━━━━━━━━━━━━━━
✖ The update clause in this loop moves the variable in the wrong direction.
> 1 │ for (var i = 10; i >= 0; i++) {
│ ^^^^^^^^^^^^^^^^^^^^^^^^^
2 │ }
3 │
for (var i = 0; i > 10; i++) {}correctness/useValidForDirection.js:1:5 lint/correctness/useValidForDirection ━━━━━━━━━━━━━━━━━━━━━━
✖ The update clause in this loop moves the variable in the wrong direction.
> 1 │ for (var i = 0; i > 10; i++) {
│ ^^^^^^^^^^^^^^^^^^^^^^^^
2 │ }
3 │
Valid
Section titled Validfor (var i = 0; i < 10; i++) {}