计算器
 
 
  
 
     
    + 
     
    = 
     
    计算 
  
 
 
 
 
 

/** 
 * Created by yanzi on 15/12/8. 
 */ 
var num1 = document.getElementById("num1"), 
  num2 = document.getElementById("num2"), 
  result = document.getElementById("result"), 
  btn_add = document.getElementById("add"); 
 
btn_add.addEventListener("click", onAddClick, false); 
function onAddClick(){ 
  var a = parseInt(num1.value), 
  b = parseInt(num2.value); 
  var sum = add(a, b); 
  result.innerHTML = sum; 
} 
 
/** 
 * 
 * @param a 
 * @param b 
 * @returns {*} 
 */ 
function add(a, b){ 
  return a+b; 
}