How to toupper char array in c?
<p>whats wrong here?</p>

<p>I want to check if the char in char array islower, so if it is it should be changed in uppercase. </p>

<pre><code>#include &lt;stdio.h&gt;

int main(int argc, char *argv[]) {
    char arr[100];
    scanf("%s",&amp;arr);
    for(int i=0;i&lt;sizeof(arr);i++){
        if(int islower(arr[i])){
            arr[i] = toupper(arr[i]);
        }
    }
    printf("%s",arr);
    return 0;
}
</code></pre>