# eqnarray*

Legacy unnumbered multi-line equation arrays kept mainly for compatibility with older documents.

https://texform.dev/latex/environments/eqnarray-star

## Metadata

| Field | Value |
| --- | --- |
| Topic | [Alignment](https://texform.dev/latex/topics/alignment) |
| Packages | ams |
| Allowed mode | math |
| Tags | math-alignment, discouraged |
| Commonality | low |
| Body mode | math |

## Syntax

### ams

Argument specification: ``

Legacy unnumbered multi-line equation arrays kept mainly for compatibility with older documents.

## Common tasks

### How to write an unnumbered equation array

```latex
\begin{eqnarray*} a &=& b+c \\ &=& d \end{eqnarray*}
```

[Open in Playground](https://play.texform.dev/?input=%5Cbegin%7Beqnarray*%7D+a+%26%3D%26+b%2Bc+%5C%5C+%26%3D%26+d+%5Cend%7Beqnarray*%7D)

### How to break a long identity without numbers

Starred form of the discouraged eqnarray environment.

```latex
\begin{eqnarray*} (a+b)^2 &=& a^2+2ab+b^2 \\ &=& a(a+2b)+b^2 \end{eqnarray*}
```

[Open in Playground](https://play.texform.dev/?input=%5Cbegin%7Beqnarray*%7D+%28a%2Bb%29%5E2+%26%3D%26+a%5E2%2B2ab%2Bb%5E2+%5C%5C+%26%3D%26+a%28a%2B2b%29%2Bb%5E2+%5Cend%7Beqnarray*%7D)

## Examples

```latex
\begin{eqnarray*} a &=& b \end{eqnarray*}
```

[Open in Playground](https://play.texform.dev/?input=%5Cbegin%7Beqnarray*%7D+a+%26%3D%26+b+%5Cend%7Beqnarray*%7D)

## Renderer support

| Package | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- |
| ams | full | none | full |

## Usage frequency

1.93% of formulas in the measured corpus contain this entry, rank 8 of 31 entries with frequency data.

## In TeXForm

TeXForm reads the environment body in math mode.

### Discouraged in ams

The LaTeX/AMS community widely discourages eqnarray-style environments because their spacing and alignment behavior are inferior to AMS alignment environments, and official amsmath guidance recommends align-family replacements instead.

```latex
\begin{eqnarray*}$1&=&$2\end{eqnarray*} -> \begin{align*}$1&=$2\end{align*}
```

The AMS align family is the standard recommended replacement, gives correct relation-spacing behavior, and has cleaner alignment/tag semantics than eqnarray-style layouts.

## See also

- [align](https://texform.dev/latex/environments/align)
- [align*](https://texform.dev/latex/environments/align-star)
- [eqnarray](https://texform.dev/latex/environments/eqnarray)
- [gather](https://texform.dev/latex/environments/gather)
- [gather*](https://texform.dev/latex/environments/gather-star)
- [split](https://texform.dev/latex/environments/split)

## Test cases

### ams

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \begin{eqnarray*} a & b \end{eqnarray*} | Positive: baseline | Pass | Fail | Pass |