TemplateString.js

const ITERATIONS = 100000000;
const RUNS = 100;

const templateStartString = function () {
  const before = new Date().getTime();
  let l = 0;
  for (let i = 0; i < ITERATIONS; i++) {
    l += `${i}def`.length;
  }
  const after = new Date().getTime();
  console.log(l);
  console.log(after-before);
  return after-before;
}

const templateMidString = function () {
  const before = new Date().getTime();
  let l = 0;
  for (let i = 0; i < ITERATIONS; i++) {
    l += `abc${i}def`.length;
  }
  const after = new Date().getTime();
  console.log(l);
  console.log(after-before);
  return after-before;
}

const templateEndString = function () {
  const before = new Date().getTime();
  let l = 0;
  for (let i = 0; i < ITERATIONS; i++) {
    l += `abc${i}`.length;
  }
  const after = new Date().getTime();
  console.log(l);
  console.log(after-before);
  return after-before;
}

const templateDoubleString = function () {
  const before = new Date().getTime();
  let l = 0;
  for (let i = 0; i < ITERATIONS; i++) {
    l += `abc${i}def${i}ghi`.length;
  }
  const after = new Date().getTime();
  console.log(l);
  console.log(after-before);
  return after-before;
}

const concatStartString = function () {
  const before = new Date().getTime();
  let l = 0;
  for (let i = 0; i < ITERATIONS; i++) {
    l += (i + 'def').length;
  }
  const after = new Date().getTime();
  console.log(l);
  console.log(after-before);
  return after-before;
}

const concatMidString = function () {
  const before = new Date().getTime();
  let l = 0;
  for (let i = 0; i < ITERATIONS; i++) {
    l += ('abc' + i + 'def').length;
  }
  const after = new Date().getTime();
  console.log(l);
  console.log(after-before);
  return after-before;
}

const concatEndString = function () {
  const before = new Date().getTime();
  let l = 0;
  for (let i = 0; i < ITERATIONS; i++) {
    l += ('abc' + i).length;
  }
  const after = new Date().getTime();
  console.log(l);
  console.log(after-before);
  return after-before;
}

const concatDoubleString = function () {
  const before = new Date().getTime();
  let l = 0;
  for (let i = 0; i < ITERATIONS; i++) {
    l += ('abc' + i + 'def' + i + 'ghi').length;
  }
  const after = new Date().getTime();
  console.log(l);
  console.log(after-before);
  return after-before;
}

const o = {
  t: {
    start: [],
    mid: [],
    end: [],
    double: []
  },
  c: {
    start: [],
    mid: [],
    end: [],
    double: []
  }
}

for (let i = 0; i < RUNS; i++) {
  console.log(`RUN ${i+1}`);
  o.t.start.push(templateStartString());
  o.t.mid.push(templateMidString());
  o.t.end.push(templateEndString());
  o.t.double.push(templateDoubleString());
  o.c.start.push(concatStartString());
  o.c.mid.push(concatMidString());
  o.c.end.push(concatEndString());
  o.c.double.push(concatDoubleString());
}
const calcs = {
  sum: {
    t: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    },
    c: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    }
  },
  avg: {
    t: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    },
    c: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    }
  },
  sd: {
    t: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    },
    c: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    }
  },
  min: {
    t: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    },
    c: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    }
  },
  max: {
    t: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    },
    c: {
      start: 0,
      mid: 0,
      end: 0,
      double: 0
    }
  }
}

const calcTemplate = function (name) {
  for (const v of o.t[name]) {
    calcs.sum.t[name] += v;
  }
  calcs.avg.t[name] = calcs.sum.t[name] / RUNS;
  for (const value of o.t[name]) {
    const v = value - calcs.avg.t[name];
    calcs.sd.t[name] += v*v;
  }
  calcs.sd.t[name] = calcs.sd.t[name] / RUNS;
  calcs.sd.t[name] = Math.pow(calcs.sd.t[name], 0.5);
  calcs.min.t[name] = Math.min(...o.t[name]);
  calcs.max.t[name] = Math.max(...o.t[name]);
}

const calcConcat = function (name) {
  for (const v of o.c[name]) {
    calcs.sum.c[name] += v;
  }
  calcs.avg.c[name] = calcs.sum.c[name] / RUNS;
  for (const value of o.c[name]) {
    const v = value - calcs.avg.c[name];
    calcs.sd.c[name] += v*v;
  }
  calcs.sd.c[name] = calcs.sd.c[name] / RUNS;
  calcs.sd.c[name] = Math.pow(calcs.sd.c[name], 0.5);
  calcs.min.c[name] = Math.min(...o.c[name]);
  calcs.max.c[name] = Math.max(...o.c[name]);
}

const calc = function () {
  calcTemplate('start');
  calcTemplate('mid');
  calcTemplate('end');
  calcTemplate('double');

  calcConcat('start');
  calcConcat('mid');
  calcConcat('end');
  calcConcat('double');
}

calc();
console.log(calcs);