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for

`for` loop to repeat specified number of times

Syntax

```for `index` = `values`
`statements`
end
```

Description

example

``````for index = values, statements, end``` executes a group of statements in a loop for a specified number of times. `values` has one of the following forms:`initVal`:`endVal` — Increment the `index` variable from `initVal` to `endVal` by `1`, and repeat execution of `statements` until `index` is greater than `endVal`.`initVal`:`step`:`endVal` — Increment `index` by the value `step` on each iteration, or decrements `index` when `step` is negative.`valArray` — Create a column vector, `index`, from subsequent columns of array `valArray` on each iteration. For example, on the first iteration, `index = valArray(:,1)`. The loop executes a maximum of `n` times, where `n` is the number of columns of `valArray`, given by `numel(valArray(1,:))`. The input `valArray` can be of any MATLAB® data type, including a character vector, cell array, or struct.```

Examples

collapse all

Create a Hilbert matrix of order 10.

```s = 10; H = zeros(s); for c = 1:s for r = 1:s H(r,c) = 1/(r+c-1); end end```

Step by increments of `-0.2`, and display the values.

```for v = 1.0:-0.2:0.0 disp(v) end```
``` 1 0.8000 0.6000 0.4000 0.2000 0 ```
```for v = [1 5 8 17] disp(v) end```
``` 1 5 8 17 ```
```for I = eye(4,3) disp('Current unit vector:') disp(I) end```
```Current unit vector: 1 0 0 0 Current unit vector: 0 1 0 0 Current unit vector: 0 0 1 0 ```

Tips

• To programmatically exit the loop, use a `break` statement. To skip the rest of the instructions in the loop and begin the next iteration, use a `continue` statement.

• Avoid assigning a value to the `index` variable within the loop statements. The `for` statement overrides any changes made to `index` within the loop.

• To iterate over the values of a single column vector, first transpose it to create a row vector.