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kotlinlang

Why I can’t convert a String (number with decimal) into Int directly?

```fun main() {
    val stringDouble = "420.0"
    val int = stringDouble.toIntOrNull()
    assert(int != null) // failed
}```

I'm guessing to prevent rounding ambiguity.

Because the method would have too many responsibilities: what can be parsed, what cannot? Should it truncate or round? How? It's easier, more readable and more flexible to compose two functions: one that parses the string to a double or BigDecimal, and one that lets you transform this double or BigDecimal to an int, the way you want to.

agree, but also, more simply: it's not an int :slightly_smiling_face:

&gt; it’s not an int
`stringDouble.toDouble()` is also not an int. But it can call `toInt()`
They got same prefix (toInt*) but do different work.