Javascript基础语法

javascript数组从头部与尾部插入与删除

push pop shift unshift

javascript对象添加与删除属性

添加方法与修改一致，直接加上去即可

删除用delete ourDog.bark;

javascript是否拥有某个属性

hasOwnProperty

javascript随机数

Math.floor(Math.random() * (ourMax – ourMin + 1)) + ourMin;

正则表达式

/ is the start of the regular expression. the is the pattern we want to match. / is the end of the regular expression. g means global, which causes the pattern to return all matches in the string, not just the first one. i means that we want to ignore the case (uppercase or lowercase) when searching for the pattern.

注意：\d表示数字，＼D表示相反

javascript数组变换

map reduce filter sort concat

var oldArray = [1, 2, 3]; var timesFour = oldArray.map(function(val){ return val * 4; }); console.log(timesFour); // returns [4, 8, 12] console.log(oldArray); // returns [1, 2, 3] var singleVal = array.reduce(function(previousVal, currentVal) { return previousVal – currentVal; }, 0); var newArray = oldArray.filter(function(val){ if(val<6){ return val; } }); sort can be passed a compare function as a callback. The compare function should return a negative number if a should be before b, a positive number if a should be after b, or 0 if they are equal. var array = [1, 12, 21, 2]; array.sort(function(a, b) { return a - b; }); var myArray = [1, 2, 3]; myArray.reverse(); 同时还有string的split与join javascript逆转字符串 function palindrome(str) { // Good luck! var re = /[^a-zA-Z0-9]/g; var t1=str.replace(re,""); var t2=t1.toLowerCase(); var temStr=t2.split("").reverse().join(""); if(temStr==t2){ return true; }else{ return false; } } palindrome("eye"); javascript将首字母变为大写，其他变为小写 function titleCase(str) { var tempStr=str.split(" "); var tempStr2=[]; for(var i=0;i=str.length){ return str; }else{ if(num<=3){ var result=str.slice(0,num); return result+"..."; }else{ var result2=str.slice(0,num-3); return result2+"..."; } } } truncateString("A-tisket a-tasket A green and yellow basket", 11); 截取数组 slice截取到数组到后一个参数－1位 function slasher(arr, howMany) { // it doesn't always pay to be first var n=arr.length; if(howMany>=n){ return []; } return arr.slice(howMany,n+1); } slasher([1, 2, 3], 2);

检测子串

function mutation(arr) { var first=arr[0]; var second=arr[1]; first=first.toLowerCase(); second=second.toLowerCase(); for(var i=0;i=65&&str.charCodeAt(i)<78){ result+=String.fromCharCode(str.charCodeAt(i)+26-13); }else if(str.charCodeAt(i)>=78&&str.charCodeAt(i)<91){ result+=String.fromCharCode(str.charCodeAt(i)-13); }else{ result+=str[i]; } } return result; } // Change the inputs below to test rot13("SERR PBQR PNZC"); 使用jquery读取json数据

javascript获取你的经纬度

javascript获取数组的最大值