Solidity Using For Example 2

pragma solidity ^0.4.0;

library SearchLib {
    function getIndexOf(uint[] storage selfStore, uint value) returns (uint) {
        for (uint n = 0; n < selfStore.length; n++)
            if (selfStore[n] == value) return n;
        return uint(-1);
    }
}

contract Cont {
    using SearchLib for uint[];
    uint[] libData;

    function append(uint value) {
        libData.push(value);
    }

    function replace(uint _oldData, uint _newData) {
        // Will perform library function call
        uint index = libData.getIndexOf(_oldData);
        if (index == uint(-1))
            libData.push(_newData);
        else
            libData[index] = _newData;
    }
}