42 lines
1.0 KiB
Markdown
42 lines
1.0 KiB
Markdown
|
# Chaining
|
||
|
|
|
||
|
|
Math.js supports chaining operations by wrapping a value into a `Chain`.
|
||
|
|
A chain can be created with the function `math.chain(value)`
|
||
|
|
(formerly `math.select(value)`).
|
||
|
|
All functions available in the math namespace can be executed via the chain.
|
||
|
|
The functions will be executed with the chain's value as the first argument,
|
||
|
|
followed by extra arguments provided by the function call itself.
|
||
|
|
|
||
|
|
```js
|
||
|
|
math.chain(3)
|
||
|
|
.add(4)
|
||
|
|
.subtract(2)
|
||
|
|
.done() // 5
|
||
|
|
|
||
|
|
math.chain( [[1, 2], [3, 4]] )
|
||
|
|
.subset(math.index(0, 0), 8)
|
||
|
|
.multiply(3)
|
||
|
|
.done() // [[24, 6], [9, 12]]
|
||
|
|
```
|
||
|
|
|
||
|
|
### API
|
||
|
|
|
||
|
|
A `Chain` is constructed as:
|
||
|
|
|
||
|
|
```js
|
||
|
|
math.chain()
|
||
|
|
math.chain(value)
|
||
|
|
```
|
||
|
|
|
||
|
|
The `Chain` has all functions available in the `math` namespace, and has
|
||
|
|
a number of special functions:
|
||
|
|
|
||
|
|
- `done()`
|
||
|
|
Finalize the chain and return the chain's value.
|
||
|
|
- `valueOf()`
|
||
|
|
The same as `done()`, returns the chain's value.
|
||
|
|
- `toString()`
|
||
|
|
Executes `math.format(value)` onto the chain's value, returning
|
||
|
|
a string representation of the value.
|
||
|
|
|