函数示例1 float circle area(int r float s s=.1416*rr return(s) main( float area, intr printf("请输入圆的半径:"); scanf(" %d", &r) printf("n area=%f\n", circle area(r)函数示例1 float circle_area (int r) { float s; s=.1416*r*r; return(s); } main( ) { float area; int r; printf("请输入圆的半径："); scanf("%d",&r); printf("\n area=%f\n",circle_area(r)); }