better-switch.js

const otherwise = () => true;

const cases = (value, branches) => {  
  for (let i = 0; i < branches.length; i += 2) {
    const predicate = branches[i];
    const action = branches[i + 1];
    
    if (predicate(value)) {
      return action();
    }
  }
}

example.js

const inRange = (a, b) => (value) => a <= value && b >= value;

let a = 11;

cases(a, [
  
  inRange(5, 10), () => {
    console.log('5 to 10!');
  },
  
  inRange(0, 5), () => {
    console.log('0 to 4!');
  },
  
  otherwise, () => {
    console.log('Default, a = ' + a + '!');
  }
  
])