JavaScript examples

compareNumeric.js

function compareNumeric(a, b) {
  if (a > b) return 1;
  if (a == b) return 0;
  if (a < b) return -1;
}

let arr = [ 2, 1, 15 ];

arr.sort(compareNumeric);

alert(arr);  // 1, 2, 15

unique.js

function uniqueSimple (array) {
  const result = []
  for (let value of array) {
    if (!result.includes(value)) {
      result.push(value)
    }
  }
  return result
}

function uniqueComplex (array, transformer) {
  const result = []
  const seen = []
  for (let value of array) {
    let computed
    if (transformer) {
      computed = transformer(value)
    } else {
      computed = value
    }
    
    if (!seen.includes(computed)) {
      seen.push(computed)
      result.push(value)
    }
  }
  return result
}