## `assertApproxEqAbs`

### Signature

```solidity
function assertApproxEqAbs(uint256 left, uint256 right, uint256 maxDelta) internal;
```

```solidity
function assertApproxEqAbs(uint256 left, uint256 right, uint256 maxDelta, string memory err) internal;
```

```solidity
function assertApproxEqAbs(int256 left, int256 right, uint256 maxDelta) internal;
```

```solidity
function assertApproxEqAbs(int256 left, int256 right, uint256 maxDelta, string memory err) internal;
```

### Description

Asserts `left` is approximately equal to `right` with delta in absolute value.

Optionally includes an error message in the revert string.

### Examples

```solidity
function testRevert() external {
    uint256 a = 100;
    uint256 b = 200;

    assertApproxEqAbs(a, b, 90);
}
```

```
[FAIL: assertion failed: 100 !~= 200 (max delta: 90, real delta: 100)] testRevert() (gas: 23884)
```

### SEE ALSO

* [`assertApproxEqAbsDecimal`](/reference/forge-std/assertApproxEqAbsDecimal.mdx)
* [`assertApproxEqRel`](/reference/forge-std/assertApproxEqRel.mdx)