is he the composer also?
Yes.
Can I Have It Like That
Williams' rap is in a throaty baritone, described as a "honey-coated version" of the styles of Snoop Dogg and Dr. Dre. He raps about his current lifestyle as well as his life and achievements. 
pharrell gwen can i have it like that It is a song. who is the singer? Pharrell Williams
wiki:669874
Can I Have It Like That [SEP] Background and composition
Stefani, however, insisted that they work on "Can I Have It Like That" then, and Williams recorded her performing the song's hook. She contributed one line, which she performed twice, to the song. Williams' rap is in a throaty baritone, described as a "honey-coated version" of the styles of Snoop Dogg and Dr. Dre. He raps about his current lifestyle as well as his life and achievements. The rap is set over a rhythm section consisting of an irregular beat and a grinding bass. The track reflects Williams' minimalist style, and it is inflected with jazz music, including a trumpet part during the bridge.