find the number of times the letter e appears:
let str = "hello everyone";if so, the methods I can think of at present are:
let num = str.split ("e"). Length-1; num = > 4 )
let reg = / str.match (reg) g; let num = str.match (reg) .length; num = > 4
is there any other way?
let str='hello everyone';
function catStr(str){
ler num=0;
for(var i=0,len=str.length;i<len;iPP){
if(str[i]=='e'){
numPP
}
}
return num
}
catStr(str)
for is the lowest performance
var strs = "hello everyone"
var num = strs.split ('') .filter (I = > I = ='e'). Length
/ / 4
Super fast!
console.time('start');
let num = 0;
let str = "hello everyone"
while(str.indexOf('e')!== -1) {
str = str.slice(str.indexOf('e') + 1)
num += 1
}
console.timeEnd('start')
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