计算 10亿 的和，js 和 c 的处理时长对比

js

4.17s

let sum = 0;
let start = new Date().getTime();
for (let i=0;i<1000000000; i=i+1){sum = sum +i;
}
let stop = new Date().getTime();
console.log((stop - start)/1000, sum);

结果：

c

3.65s

#include "stdio.h"
#include "time.h"
#include <sys/time.h>int main() {struct timeval start, stop;gettimeofday(&start, NULL);double sum = 0;for (double i=0;i<1000000000; i=i+1){sum+=i;}gettimeofday(&stop, NULL);float diffMs = (float )(stop.tv_usec - start.tv_usec)/1000;float difS = (float )(stop.tv_sec - start.tv_sec);printf("s: %f, ms: %f\n", difS, diffMs);if (diffMs < 0){difS = difS - 1 + (1 * 1000 + diffMs)/1000;} else {difS = difS + diffMs/1000;}printf("sum = %.0f\n", sum);printf("diff is : %.3fs", difS);}

结果：