javascript 反向字符串到位

Posted 2021-05-03

function reverse(arrayOfChars) {
  for(let i = 0; i < Math.floor(arrayOfChars.length/2); i++) {
    let bucket = arrayOfChars[i];
    arrayOfChars[i] = arrayOfChars[arrayOfChars.length - (i+1)];
    arrayOfChars[arrayOfChars.length - (i+1)] = bucket;
  }
}

// Tests

let desc = 'empty string';
let input = ''.split('');
reverse(input);
let actual = input.join('');
let expected = '';
assertEqual(actual, expected, desc);

desc = 'single character string';
input = 'A'.split('');
reverse(input);
actual = input.join('');
expected = 'A';
assertEqual(actual, expected, desc);

desc = 'longer string';
input = 'ABCDE'.split('');
reverse(input);
actual = input.join('');
expected = 'EDCBA';
assertEqual(actual, expected, desc);

function assertEqual(a, b, desc) {
  if (a === b) {
    console.log(`${desc} ... PASS`);
  } else {
    console.log(`${desc} ... FAIL: ${a} != ${b}`);
  }
}