每天一點原生JS

1、連字元字元串轉駝峰——方法1

var a = "first-second-third";

function test(str){
var arr = str.split('-');
for (var i = 1; i < arr.length; i++){
arr[i] = arr[i].charAt(0).toUpperCase() + arr[i].substring(1);
}
return arr.join('');
}

alert(test(a))

連字元字元串轉駝峰——方法2

function test2(str){
var re = /-(\w)/g;

return str.replace(re, function($0, $1){
return $1.toUpperCase();
})
}

alert(test2(a))

var b = 'sbrfsajhjssssskjdksss';

		var obj = {};

		var max = 0;

		var value = '';

		function charMax(str){
			for (var i = 0; i < str.length; i++){
				if(!obj[str[i]]){
					obj[str[i]] = [];
				}
				obj[str[i]].push(str[i])
			}

			for(var attr in obj){
				if(max < obj[attr].length){
					max = obj[attr].length;
					value = attr;
				}
			}

			return '最多的字元是' + value + '，長度為' + max;
		}

		alert(charMax(b));

　　方法2：

function charMax2(str){

			var arr = str.split('');

			arr.sort();

			str = arr.join('');

			var re = /(\w)\1+/g;

			var max = 0;

			var value = '';

			str.replace(re, function($0, $1){
				if(max < $0.length){
					max = $0.length;
					value = $1;
				}
			})

			return '最多的字元是' + value + '，長度為' + max; 

		}

		alert(charMax2(b));