**Ruby**
```{.ruby}
# one-liner
p ([*1..10000]*'').count '8' #=>4000
```
```{.ruby}
# for test
counter = ->num,s {([*1..num]*'').count s}
```
**Test**
```{.ruby}
expect(counter[10000,'8']).to eq 4000
```
**Ruby**
```{.ruby}
# one-liner
p ([*1..10000]*'').count '8' #=>4000
```
```{.ruby}
# for test
counter = ->num,s {([*1..num]*'').count s}
```
**Test**
```{.ruby}
expect(counter[10000,'8']).to eq 4000
```