9 examples of 'javascript multiply array' in JavaScript

5
function multiply(array) {
6
  // write code here
7
  if (!array || array.length === 0) {
8
    return [];
9
  }
10
  let processArr = [1];
11
  let length = array.length;
12
  // 0 ~ i 数组
13
  //     对于第一个for循环
14
  // 第一步：b[0] = 1;
15
  // 第二步：b[1] = b[0] * a[0] = a[0]
16
  // 第三步：b[2] = b[1] * a[1] = a[0] * a[1];
17
  // 第四步：b[3] = b[2] * a[2] = a[0] * a[1] * a[2];
18
  // 第五步：b[4] = b[3] * a[3] = a[0] * a[1] * a[2] * a[3];
19
  for (let i = 1; i < length; i++) {
20
    processArr[i] = processArr[i - 1] * array[i - 1];
21
  }
22
  console.log(processArr);
23
  // i + 1 ~ length - 1
24
  let temp = 1;
25
  for (let i = length - 1; i > 0; i--) {
26
    temp *= array[i];
27
    processArr[i - 1] = processArr[i - 1] * temp;
28
  }
29
  return processArr;
30
}

42
export function multiply(a, b) {
43
  const a00 = a[0], a01 = a[1], a02 = a[2];
44
  const a10 = a[3], a11 = a[4], a12 = a[5];
45
  const a20 = a[6], a21 = a[7], a22 = a[8];
46
47
  const b00 = b[0], b01 = b[1], b02 = b[2];
48
  const b10 = b[3], b11 = b[4], b12 = b[5];
49
  const b20 = b[6], b21 = b[7], b22 = b[8];
50
51
  a[0] = b00 * a00 + b01 * a10 + b02 * a20;
52
  a[1] = b00 * a01 + b01 * a11 + b02 * a21;
53
  a[2] = b00 * a02 + b01 * a12 + b02 * a22;
54
55
  a[3] = b10 * a00 + b11 * a10 + b12 * a20;
56
  a[4] = b10 * a01 + b11 * a11 + b12 * a21;
57
  a[5] = b10 * a02 + b11 * a12 + b12 * a22;
58
59
  a[6] = b20 * a00 + b21 * a10 + b22 * a20;
60
  a[7] = b20 * a01 + b21 * a11 + b22 * a21;
61
  a[8] = b20 * a02 + b21 * a12 + b22 * a22;
62
63
  return a;
64
}

12
function multiply (a: [ number, number ], b: [ number, number ]): [ number, number ] {
13
    return [ ((a[0] * b[0]) - (a[1] * b[1])), ((a[0] * b[1]) + (a[1] * b[0])) ];
14
}

41
export function multiply(a, b) {
42
  return [
43
    a[0] * b[0] + a[1] * b[3] + a[2] * b[6],
44
    a[0] * b[1] + a[1] * b[4] + a[2] * b[7],
45
    a[0] * b[2] + a[1] * b[5] + a[2] * b[8],
46
    a[3] * b[0] + a[4] * b[3] + a[5] * b[6],
47
    a[3] * b[1] + a[4] * b[4] + a[5] * b[7],
48
    a[3] * b[2] + a[4] * b[5] + a[5] * b[8],
49
    a[6] * b[0] + a[7] * b[3] + a[8] * b[6],
50
    a[6] * b[1] + a[7] * b[4] + a[8] * b[7],
51
    a[6] * b[2] + a[7] * b[5] + a[8] * b[8]
52
  ];
53
}

3
function multiply(a, b) {
4
  return a * b;
5
}

44
export function multiply (C: Matrix, A: Matrix, B: Matrix) {
45
  let i = 0
46
  let j = 0
47
  let k = 0
48
  let Ap = 0
49
  let pA = 0
50
  let pB = 0
51
  let _pB = 0
52
  let Cp = 0
53
  const ncols = A.cols
54
  const nrows = A.rows
55
  const mcols = B.cols
56
  const ad = A.data
57
  const bd = B.data
58
  const cd = C.data
59
  let sum = 0.0
60
61
  for (; i < nrows; Ap += ncols, i++) {
62
    for (_pB = 0, j = 0; j < mcols; Cp++, _pB++, j++) {
63
      pB = _pB
64
      pA = Ap
65
      sum = 0.0
66
      for (k = 0; k < ncols; pA++, pB += mcols, k++) {
67
        sum += ad[pA] * bd[pB]
68
      }
69
      cd[Cp] = sum
70
    }
71
  }
72
}

46
function multiply( C, A, B ){
47
    var i=0,j=0,k=0;
48
    var Ap=0,pA=0,pB=0,p_B=0,Cp=0;
49
    var ncols=A.cols,nrows=A.rows,mcols=B.cols;
50
    var ad=A.data,bd=B.data,cd=C.data;
51
    var sum=0.0;
52
53
    for (; i < nrows; Ap += ncols, i++) {
54
        for (p_B = 0, j = 0; j < mcols; Cp++, p_B++, j++) {
55
            pB = p_B;
56
            pA = Ap;
57
            sum = 0.0;
58
            for (k = 0; k < ncols; pA++, pB += mcols, k++) {
59
                sum += ad[pA] * bd[pB];
60
            }
61
            cd[Cp] = sum;
62
        }
63
    }
64
}

1091
function multiply(out, a, b) {
1092
    var a00 = a[0], a01 = a[1], a02 = a[2], a03 = a[3],
1093
        a10 = a[4], a11 = a[5], a12 = a[6], a13 = a[7],
1094
        a20 = a[8], a21 = a[9], a22 = a[10], a23 = a[11],
1095
        a30 = a[12], a31 = a[13], a32 = a[14], a33 = a[15];
1096
1097
    // Cache only the current line of the second matrix
1098
    var b0  = b[0], b1 = b[1], b2 = b[2], b3 = b[3];  
1099
    out[0] = b0*a00 + b1*a10 + b2*a20 + b3*a30;
1100
    out[1] = b0*a01 + b1*a11 + b2*a21 + b3*a31;
1101
    out[2] = b0*a02 + b1*a12 + b2*a22 + b3*a32;
1102
    out[3] = b0*a03 + b1*a13 + b2*a23 + b3*a33;
1103
1104
    b0 = b[4]; b1 = b[5]; b2 = b[6]; b3 = b[7];
1105
    out[4] = b0*a00 + b1*a10 + b2*a20 + b3*a30;
1106
    out[5] = b0*a01 + b1*a11 + b2*a21 + b3*a31;
1107
    out[6] = b0*a02 + b1*a12 + b2*a22 + b3*a32;
1108
    out[7] = b0*a03 + b1*a13 + b2*a23 + b3*a33;
1109
1110
    b0 = b[8]; b1 = b[9]; b2 = b[10]; b3 = b[11];
1111
    out[8] = b0*a00 + b1*a10 + b2*a20 + b3*a30;
1112
    out[9] = b0*a01 + b1*a11 + b2*a21 + b3*a31;
1113
    out[10] = b0*a02 + b1*a12 + b2*a22 + b3*a32;
1114
    out[11] = b0*a03 + b1*a13 + b2*a23 + b3*a33;
1115
1116
    b0 = b[12]; b1 = b[13]; b2 = b[14]; b3 = b[15];
1117
    out[12] = b0*a00 + b1*a10 + b2*a20 + b3*a30;
1118
    out[13] = b0*a01 + b1*a11 + b2*a21 + b3*a31;
1119
    out[14] = b0*a02 + b1*a12 + b2*a22 + b3*a32;
1120
    out[15] = b0*a03 + b1*a13 + b2*a23 + b3*a33;
1121
    return out;
1122
};

26
export function multiply(
27
  a: Vector,
28
  b: Vector | number
29
): Vector | number {
30
  return math.multiply(a, b) as Vector | number;
31
}