## how can i compute the length of an integer?

on 4 Jan 2013

if i have

int = 12345;

length_int = 5;

???

Jan Simon

### Jan Simon (view profile)

on 4 Jan 2013

What is the "length" of -1 and 0?

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### Azzi Abdelmalek (view profile)

on 4 Jan 2013
Edited by Azzi Abdelmalek

### Azzi Abdelmalek (view profile)

on 4 Jan 2013

```int=-123456789
max(ceil(log10(abs(int))),1)
```

### Sean de Wolski (view profile)

on 4 Jan 2013
Edited by Sean de Wolski

### Sean de Wolski (view profile)

on 4 Jan 2013

Edit

```nnz(num2str(int) - '-')
```

Sean de Wolski

### Sean de Wolski (view profile)

on 4 Jan 2013

Friedrich, neither work actually, consider -12345.

Friedrich

### Friedrich (view profile)

on 4 Jan 2013

Good point Sean. But then

```numel(num2str(abs(int)))
```

should do ;)

Sean de Wolski

on 4 Jan 2013

arghh, you win!

### Davide Ferraro (view profile)

on 4 Jan 2013

Casting the variable into a string may be risky because you may get to "unexpected" cases such as:

```    int = 12345678901234567890123
numel(num2str(int))
ans =```
`      12`

You may consider a numeric approach using LOG10: floor(log10(int))+1 all numbers between 10 and 100 will have a LOG10 between 1 and 2 so you can use FLOOR to get the lower value (1 in this case) and then you need to add the value 1 cause you are trying to compute the number of digits and not the power of ten.

G A

### G A (view profile)

on 4 Jan 2013

why, it works:

` >> int = 12345678901234567890123`
`    numel(num2str(int))`
```int =
```
`   1.2346e+22`
```ans =
```
`    23`

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