将if语句转换为for循环？

Question

我在mikroC中编写了一个函数,用于扫描4x4键盘中的按键

void scan_key()
{
    PORTB = 0B11111110;
    if ( PORTB == 0b11101110){
        Row = 1;
        Column = 1;
        return;
    }
    if ( PORTB == 0b11011110){
        Row = 2;
        Column = 1;
        return;
    }
    if ( PORTB == 0b10111110){
        Row = 3;
        Column = 1;
        return;
    }
    if ( PORTB == 0b01111110){
        Row = 4;
        Column = 1;
        return;
    }

    PORTB = 0B11111101;
    if ( PORTB == 0b11101101){
        Row = 1;
        Column = 2;
        return;
    }
    if ( PORTB == 0b11011101){
        Row = 2;
        Column = 2;
        return;
    }
    if ( PORTB == 0b10111101){
        Row = 3;
        Column = 2;
        return;
    }
    if ( PORTB == 0b01111101){
        Row = 4;
        Column = 2;
        return;
    }

    PORTB = 0B11111011;
    if ( PORTB == 0b11101011){
        Row = 1;
        Column = 3;
        return;
    }
    if ( PORTB == 0b11011011){
        Row = 2;
        Column = 3;
        return;
    }
    if ( PORTB == 0b10111011){
        Row = 3;
        Column = 3;
        return;
    }
    if ( PORTB == 0b01111011){
        Row = 4;
        Column = 3;
        return;
    }

    PORTB = 0B11110111;
    if ( PORTB == 0b11100111){
        Row = 1;
        Column = 4;
        return;
    }
    if ( PORTB == 0b11010111){
        Row = 2;
        Column = 4;
        return;
    }
    if ( PORTB == 0b10110111){
        Row = 3;
        Column = 4;
        return;
    }
    if ( PORTB == 0b01110111){
        Row = 4;
        Column = 4;
        return;
    }

    PORTB = 0B11110000;
}

有没有办法将此算法转换为循环？

Answer 1

是.(至少假设你实际上并不是指在每个ifs 块之前都有这些赋值.我假设它们在那里进行测试？否则你的代码没有意义.)

至少,您可以将每个二进制值放入一个数组中,并构造一个这样的循环:

int portValue[4][4] = {{0b11101110, 0b11011110, 0b10111110, 0b01111110}, {//...Rest of values here }}

int loop_col = 0;
int loop_row = 0;

for (loop_col = 0; loop_col < 4; loop_col++){
    for (loop_row = 0; loop_row < 4; loop_row++){
         if ( PORTB == portValue[loop_col][loop_row]){
             Row = loop_row + 1;
             Column = loop_col + 1;
             return;
         }
    }
}