forloop in js

1var colors=["red","blue","green"];
2for (let i = 0; i < colors.length; i++) { 
3  console.log(colors[i]);
4}

1for (var i; i < 10; i++) {
2  
3}

1for (let count = 0; count < 90; count++) {
2	// ...
3}

1var i;
2for (i = 0; i < 10 ; i++) {
3  //do something
4}

1var listItem = [
2        {name: 'myName1', gender: 'male'},
3        {name: 'myName2', gender: 'female'},
4        {name: 'myName3', gender: 'male'},
5        {name: 'myName4', gender: 'female'},
6      ]
7
8    for (const iterator of listItem) {
9        console.log(iterator.name+ ' and '+ iterator.gender);
10    }

1for(i = 0; i < x; ++i){
2  //Loop, x can be replaced with any integer; 
3}