binary-bitwise-left-shift.js 1.7 KB

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  1. test("basic numeric shifting", () => {
  2. expect(0 << 0).toBe(0);
  3. expect(0 << 1).toBe(0);
  4. expect(0 << 2).toBe(0);
  5. expect(0 << 3).toBe(0);
  6. expect(0 << 4).toBe(0);
  7. expect(0 << 5).toBe(0);
  8. expect(1 << 0).toBe(1);
  9. expect(1 << 1).toBe(2);
  10. expect(1 << 2).toBe(4);
  11. expect(1 << 3).toBe(8);
  12. expect(1 << 4).toBe(16);
  13. expect(1 << 5).toBe(32);
  14. expect(2 << 0).toBe(2);
  15. expect(2 << 1).toBe(4);
  16. expect(2 << 2).toBe(8);
  17. expect(2 << 3).toBe(16);
  18. expect(2 << 4).toBe(32);
  19. expect(2 << 5).toBe(64);
  20. expect(3 << 0).toBe(3);
  21. expect(3 << 1).toBe(6);
  22. expect(3 << 2).toBe(12);
  23. expect(3 << 3).toBe(24);
  24. expect(3 << 4).toBe(48);
  25. expect(3 << 5).toBe(96);
  26. expect(4 << 0).toBe(4);
  27. expect(4 << 1).toBe(8);
  28. expect(4 << 2).toBe(16);
  29. expect(4 << 3).toBe(32);
  30. expect(4 << 4).toBe(64);
  31. expect(4 << 5).toBe(128);
  32. expect(5 << 0).toBe(5);
  33. expect(5 << 1).toBe(10);
  34. expect(5 << 2).toBe(20);
  35. expect(5 << 3).toBe(40);
  36. expect(5 << 4).toBe(80);
  37. expect(5 << 5).toBe(160);
  38. expect(0xffffffff << 0).toBe(-1);
  39. expect(0xffffffff << 16).toBe(-65536);
  40. expect(0xffff0000 << 16).toBe(0);
  41. expect(0xffff0000 << 15).toBe(-2147483648);
  42. });
  43. test("shifting with non-numeric values", () => {
  44. let x = 3;
  45. let y = 7;
  46. expect("42" << 6).toBe(2688);
  47. expect(x << y).toBe(384);
  48. expect(x << [[[[12]]]]).toBe(12288);
  49. expect(undefined << y).toBe(0);
  50. expect("a" << "b").toBe(0);
  51. expect(null << null).toBe(0);
  52. expect(undefined << undefined).toBe(0);
  53. expect(NaN << NaN).toBe(0);
  54. expect(NaN << 6).toBe(0);
  55. expect(Infinity << Infinity).toBe(0);
  56. expect(-Infinity << Infinity).toBe(0);
  57. });